Doctor vs Predator

by Otaku Hikikimori

When the Doctor and Ace accidentally arrive in the middle of the Battle of Stalingrad in 1942 they soon discover that soldiers aren't the only things stalking the ruins...

PROLOGUE

STALINGRAD, OCTOBER 1942

Oberleutnant Hans Cuiper assembled his patrol in the hour before dawn. The men stumbled from their bolt holes in the rubble, stretching stiff and aching limbs and whispering bitter and well-worn complaints about the cold before shuffling reluctantly to their assembly point. They gathered in a patch of open ground at the rear of the gutted shell of an apartment building, just behind the forward edge of the advance. Cuiper watched as his NCOs chided and harried the men into readiness in the dark, moving amongst them as they loaded weapons, primed grenades and carefully draped long tinkling belts of machine gun ammunition over their shoulders. They prepared in near silence, the pre-dawn quiet broken only by occasional coughs, the muttered instructions of the noncoms and the faint popping sound of gunfire further north and south along the front line, rat-a-tat-tatting in the distance. As the time for their departure grew near even these faint sounds subsided, until the group waited in silence, crouched in a rough semi-circle around their leader. Cuiper was uncomfortably aware that all eyes were upon him, waiting for the dreaded yet inevitable order to move out. He checked his watch, eyes straining to make out the hands in the dark. Four minutes.

As the first pale streaks of light touched the sky to the east the silhouettes of the group before him grew slowly clearer until they resolved themselves into the shapes of men. He surveyed his patrol as the light revealed them to him, noting their ragged, filthy uniforms, their gaunt and weary faces and haunted eyes. These, he thought, were the faces of men who had been on the frontline too long, men who had fought their way across the plains and steppes and forests of half a continent to reach this concrete graveyard on the banks of the Volga. My men, he thought, and sought out the familiar faces amongst the group that crowded around him: Gruber, the platoon sergeant, a round and jolly butcher from Essen before the war, now worn lean and grim faced, squatting patiently at the front of the group; Pleiss, the foul-mouthed machine gunner, an apprentice mechanic from Hamburg in peacetime, quietly spitting on the cracked concrete floor; Nilsen, the philosophy student from Strasbourg, leaning heavily on his rifle, arms wrapped around it like vines; Clausen; Stolz; Griese, and all of the others. All my men, thought Cuiper, all of them my responsibility. Waiting for him to lead them out from the lines into the unknown wasteland before them, and trusting in him to bring them back again.

Cuiper checked his watch again (one minute fifty seconds), licked his lips nervously, checked his watch once more (one minute forty eight seconds). He passed his hands over his submachinegun, running through the checks he had done so many thousand times before: full magazine inserted, a bullet in the breech, bolt locked back into safe position; ready. He raised his eyes to Gruber and nodded once. He saw Gruber's face fall, as if some small part of him had still hoped for a reprieve, a last minute cancellation and the chance to return to the relative safety of their makeshift burrows, but he returned the nod nonetheless and took a last round of checks of the men: all present, weapons loaded, ammunition packed; ready.

Cuiper took another look at his watch, his eyes following the second hand in its course around the face. Thirty seconds. Twenty five seconds. Twenty seconds. An eternity passed. Fifteen seconds. Ten. Nine. Eight. . .

Cuiper raised a hand and watched the men tense and stiffen, saw them shifting their loads in readiness for movement. Even in his exhaustion he felt a surge of pride at their readiness to follow him out into whatever was waiting for them. Six. Five. Four. He stood and turned in the direction of the front line, aware of the men rising behind him. Which of them won't be coming back this time? he thought sadly. He turned back and motioned to Gruber, who in turn sent the scouts trotting out ahead of them with quick gestures of his hand. Cuiper took one last look at his watch. Three.

Two.

One.

"Let's go," he hissed to Gruber and then followed the scouts out into the streets of the shattered city, the men filing silently after him.

o o o

They found what they were looking for in a side street running between two larger thoroughfares, littered with chunks of brick and concrete fallen from the buildings on either side. Langhoff, one of the scouts, jogged across the open space of the road ahead of them and disappeared into the covering rubble on the other side of the street. The rest of the patrol lay hidden amongst the ruins, peering suspiciously into the darkened windows of the derelict buildings around them and listening to the dull crump of a far-off artillery barrage, waiting for Langhoff to re-emerge and wave them forward. When his head reappeared however he held up the hand signals for patrol halt and then danger ahead. Sergeant Gruber took one quick look at Oberleutnant Cuiper, just long enough to register his nod of assent, and then scrambled up out of cover and hurried across the street to join Langhoff. He returned within a minute, sprinting over the road to rejoin the patrol. Keeping low, he picked his way along the line of men until he huddled by Cuiper's side.

"Found one sir," he whispered, casting his gaze into the shadows around their position as he spoke.

"A signaller?" asked Cuiper.

"Yes sir," replied Gruber.

"Dead?" asked Cuiper, already knowing the answer, and then bit anxiously at his lip when Gruber nodded an affirmative. He raised his head out of cover and peered out over the road. "Alright Sergeant. We'll go across in two groups." He looked down the line of the patrol. "I'll take Nilsen, Stolz, Reimer, Gogel and Braun. You stay here and give cover then follow with the rest once we're across." Gruber gave a curt acknowledgement and scurried back along the row of men, tapping the men who were to be first to cross on the back and whispering instructions. By the time he reached the far end of the line of men they were already in position, half of them squatting on their haunches, ready to spring up and across the street with Cuiper, the others flicking off safety catches and settling into firing postures, ready to give covering fire.

Taking a deep breath, and a last look up and down the length of the road, Cuiper jumped to his feet and rushed to the piles of rubble lining the other side of the street. He heard rather than saw the others hurrying after him and had barely stopped moving when the last of them dropped into cover beside him. Nearby lay Langhoff, submachinegun cradled in his arms. Like all of the men who volunteered to be lead scout his eyes were never still, checking windows and doors and pools of shadow.

Cuiper rose up out of cover long enough to signal Gruber's group to cross and then ducked back down. Within seconds the remainder of the patrol had crossed and taken cover with their comrades. Cuiper and Sergeant Gruber made their way to where Langhoff waited, peering down a side alley. The scout barely seemed to acknowledge their presence, eyes fixed on a shape lying amongst the litter of masonry twenty metres further down the alley. As Cuiper's eyes adjusted to the light the shape became a man, limbs arranged in a sprawl around him. A German Army helmet lay at an arms length from the body.

"Might only be wounded," said Cuiper hopefully but Langhoff slowly shook his head.

"Are you sure?" he persisted. He flicked a look at Gruber but the sergeant's gaze was fixed on the alley. "How can you tell?"

"The helmet," hissed Langhoff. His eyes were in constant motion, roving over all the places around them that might conceivably hide a man.

"What about it?" asked Cuiper. He peered more closely at the helmet, lying a metre or so from the body, trying to make out details, but in the dim light of the alley he was only barely able to see it at all.

"It's still got the head in it," whispered the scout, nodding in its direction.

Cuiper and Gruber exchanged glances.

"We need to take a closer look," said Cuiper quietly. He tapped Langhoff on the arm and motioned him forward and then leant closer to his sergeant. "Bring the men up.

o o o

The hunter waited, patient as stone. It had detected the sounds of movement some time ago and had taken up position in the upper storeys of a building overlooking the alley where its last victim lay. It had sat motionless as the shapes below had crossed the street towards it, first one man and then the rest in two scurrying groups. In the cold air their heat signatures were like beacons, their sweating bodies glowing through the flimsy rags that they wore. It noted their attempts to hide themselves among the ice-cold ruins with something like contempt. It had been willing to tolerate their approach thus far, but now they were pressing on they were entering its territory. Now they were drawing nearer to The Site.

This could not be allowed.

o o o

Langhoff loped cautiously past the body to the far end of the alley and took up position there while Cuiper approached the body. Behind him, Gruber led the rest of the patrol out of cover and motioned them to take up station against the walls of the buildings on both sides.

Cuiper had seen literally hundreds of dead bodies over the last two years, many of them at close hand, so he approached this one without trepidation. Just another dead German soldier, he thought bitterly. He crouched down alongside it, placing his submachinegun on the floor by his side, and used both hands to roll the hard, frozen mass of the body onto its back. The stump of its neck where it emerged from the top of the smock was sheared off as cleanly as Cuiper had ever seen, leaving a smooth cross section of flesh and bone poking out of the collar, neat as a tailor's dummy.

From the shadows at the base of the building in front of him, Gruber gave a short low whistle. When Cuiper looked across at him Gruber raised a hand from the stock of his rifle and pointed towards an object lying a few metres further down the alley. Cuiper looked to where the sergeant was pointing and saw a signallers reel, a round metal drum mounted within a tubular metal frame, lying on its side. Cuiper was used to seeing them strapped to the backs of the signals troops, wound about with dozens of metres of cable for laying phone lines, but this one was bare, the cable all stripped off the drum.

Taken, thought Cuiper, just like the others. He looked up and down the alley as if he might see the stolen wire there but the only things to be seen apart from his own men were scattered chunks of masonry, blasted out of the sides of the buildings by shot and shell and bomb.

He scooped up his submachinegun from beside the fallen signaller's body and paced towards the empty reel, scanning the ground as he went. The ground was rimed with frost, sparkling feebly in the few patches of light that reached the alley through the jagged holes in the surrounding buildings, and as Cuiper approached the empty metal frame he saw fresh marks on the ground around it, snaking lines the width of a cable scored in the thin layer of frost, leading towards the far end of the alley where Langhoff crouched.

He paused and stooped over the tracks in the icy surface, tracing them with his gloved fingers. Why take the line? he thought. Why not just cut it? Is Ivan that short of materiel? He found himself wondering if they were closer to victory then he knew. His mind raced with possibilities. He closed his eyes for a second and the fantasies that every man in the Wehrmacht harboured but dared not speak flashed before his mind's eye: the Red Army surrendering, pouring, defeated, out of their rat-holes in the ruins, hands held high. And then home, he thought, glancing around at the shadowed shapes of his men leant against the walls on either side. At last, we'll all go home.

o o o

From its vantage point in the building above the alley the hunter watched the group's leader, stooping and poking and prodding at objects on the floor. Another human had moved to the end of the alley, searching ahead of the group while the rest clustered near to the leader, hunched against the walls.

Time to act.

The hunter moved back into the gloom of the building interior and went to a hole in the middle of the floor. The hole began in the roof above and plunged through five floors to the basement, mute testament to the trajectory of a falling shell, and the hunter dropped easily through the rough-edged gaps, descending three stories in seconds until it reached the room in the first storey that looked out over the men below. The outer wall of the building above the alley was smashed open on this floor in a wound of crumbled brick and splintered wood and when the hunter stalked silently to the opening it reacquired its targets, now just a few metres below it.

The hunter was an expert on the behaviour of herds and the one beneath it acted as had the others that it had seen on a dozen different worlds. They would take their cue from the leader and would move when he rose and led them towards the lone scout at the end of the alley; that was the moment to strike. And so it placed its targeting systems on standby, primed its weapon for firing and waited.

When the leader moved the group would move with him.

And then it would kill them all.

o o o

Cuiper looked up from the tracks of the stolen wire scored into the frost and turned to see Gruber looking questioningly at him. The officer looked back and for a moment the thought of leading the patrol back to the lines flashed through his mind. We found another dead signaller Colonel. Ivan is definitely stealing phone lines for some reason. Can we go home now? He dismissed the thought in disgust. He was a German officer with a job to do and he would damn well do it.

He motioned Gruber towards him and waited while the sergeant scuttled across to him. "We're going to follow the tracks," he said, pointing to the marks on the floor. "Tell the men not to bunch up and to keep their eyes open. Whoever did this is good; he doesn't need us to help him by getting sloppy." He waited until Gruber nodded his assent and then slowly rose from his crouch. He was about to instruct Gruber how to deploy the men when he noticed the sergeant was standing stock-still and was looking at him strangely, staring at his chest. He looked down, following the man's eyes, and noticed a strange mark on his tunic: three red points of light arranged in a triangle centred near his heart. The points danced on his chest as he moved but always returned to their position near the centre of his chest.

Cuiper brushed ineffectually at the mark with his free hand. Gruber moved forward to get a closer look, inclining his head and leaning in close and as he did so the points disappeared.

"What the-" began Gruber, puzzled, and then there was a flash of green light and a tearing sound and his head disappeared in a spray of red mist.

Time stopped. Cuiper stood open mouthed as the headless body of his sergeant swayed and slowly toppled forward, trailing thin streamers of blood as it fell. Cuiper reached out to catch him and fell back heavily as the dead weight tumbled into him. For what felt like an age but was, in reality, only a few seconds, he sat there on the frozen ground, arms out to support the sagging bulk of Gruber's headless corpse.

The sound of screams and gunshots broke him from the trance. Sniper, he thought numbly. Must be a sniper- He pushed the sergeant's body away and clambered to his feet, cocking his submachinegun as he did so. The scene around him was chaos. The rest of the patrol were all firing now, the single cracking reports of the men with rifles interspersed with the clatter of submachineguns and the longer buzzsaw-like bursts from Pleiss's machinegun. They fired wildly, seemingly at nothing, stitching the walls of the buildings around them with bullets that pocked the surface of the walls with sudden eruptions of dust. The alley was full of gunshots and shouted curses and cries. There was another ripping sound, another flash of green light, then another, and another. Some of the shouts became screams. The air was stained with the smells of gunpowder and blood.

My men, thought Cuiper desperately. My responsibility. The raking bursts from the machinegun had ceased. Cuiper looked around the alley, trying to take stock. At least three other men besides Gruber and the dead signaller now lay sprawled across the ground, smoking ruin where heads and chests once were. Cuiper recognised Pleiss lying slumped on the floor next to his machine gun, its barrel smoking in the chill air. His face looked surprised, his eyes staring into nothing. At the far end of the alley a few of the patrol were retreating back the way they had come, firing as they went, only to fall to more sudden bursts of light. There were only two others left standing in the alley with him now, Cuiper saw: Langhoff, the scout, firing his submachinegun in short bursts into the openings in the walls around them as he retreated, and Griese, squatting up against the wall, working the bolt of his rifle like a madman and firing blindly in all directions.

Looking wildly around him for a target, Cuiper raised his submachinegun and, like Langhoff, began firing into the windows and shellholes of the buildings above. The weapon shook in his hands as he fired and the vibration brought him back to his senses. He started to ape the scout's movements, backing away down the alley as he fired. As he retreated he passed the crouching figure of Griese, still frantically working the action of his rifle and firing randomly, aiming at nothing. He yelled at the man to get up and follow and, when Griese ignored him, he ducked closer to him and reached out a hand to grab him by the collar, dragging him along with him until Griese caught the idea and lurched to his feet to stumble alongside him. He continued to fire until he heard the tell-tale click of an empty chamber. As he groped in his webbing pouches for another magazine he suddenly realised that the alley was now silent apart from the ragged breathing of Griese beside him and the frantic pounding of his own heart. He turned about and, yelling at Griese to follow him, made to run the last few metres to cover.

And then he stopped, gaping at the sight before him.

Langhoff hung in mid-air before him in the middle of the alley, swaying slightly back and forth, his limbs splayed out. Two points of shining metal protruded from his stomach and he seemed to hang suspended from them, floating half a metre off the ground. His submachinegun fell from his hand as he gently bobbed in the air and dropped to the floor at his feet. His head swayed drunkenly, his eyes rolling in their sockets. He opened his mouth as if to speak but spat a rivulet of blood down the front of his tunic instead.

The air behind him was wrong somehow, shimmering like a heat haze. As Cuiper watched, paralysed by the sheer implausibility of the spectacle, the scout's body rocked to one side and then flew violently in the other direction, impacting the side of the alley with a wet thud before sliding down the wall to the floor in a smear of blood.

Cuiper sensed Griese falling to his knees beside him, letting his rifle fall clattering to the floor. He heard him mumbling what sounded like a prayer. In front of them, in the space where Langhoff had floated, the air seemed to ripple and bend. Cuiper watched, open mouthed, as the light ebbed and flowed around the edges of a monstrous man-shaped figure appearing out of the air before him. It stood two metres tall and more, powerful limbs clad in green-black armour; thick ropes of what looked like hair grew from the sides of the faceless helmet that crowned it.

It gave off a sound like a rattling snarl and took a single step forward. Shaking, Cuiper raised his submachinegun and pulled the trigger.

Click.

He looked down at his empty weapon and then up again at the armoured giant, and then there was a blur of muscle and flashing metal and he never saw anything, ever again.

CHAPTER ONE

"Nineteenth-century Russia!" exclaimed the Doctor, rolling the last "r" around his mouth exhuberantly before allowing it to escape. He strode around the central console of the TARDIS slapping at buttons and flicking switches with deft little flourishes of his hand. "The endless Southern steppes! The mighty Volga, longest river in Europe, cradle of Russian civilisation!" He paused to make a minute adjustment to a dial on the instrument panel before resuming his flamboyant circuit of the room. "Land of the Tsars! Home of Tolstoy, Dostoyevsky, Tchaikovsky-"

"Do they have a Burger King?" asked Ace hopefully.

The interruption halted the Doctor in mid-stride as if slapped. "Do they have a what?"

"A Burger King," said Ace. "I could murder a Whopper."

The Doctor regarded her balefully. "No," he said, icily. "They do not," he continued, enunciating every word very precisely, "have a Burger King."

"McDonalds?" asked Ace.

"They have," continued the Doctor, ignoring her, "Museums, art and literature. They have magnificent palaces, majestic cathedrals and mighty fortresses. They have vast wildernesses which they will, over the course of decades and centuries, hack and hew and carve into an empire stretching from the Baltic Sea to the Pacific Ocean, from the frozen wastes of the Arctic Circle to the deserts of Dagestan. They do not," he said, turning the disdain in his voice up to its maximum level, "have burger bars."

"Not even Russian ones?"

"Your problem, Ace," began the Doctor loftily (here we go, thought Ace), "is that you are incapable of appreciating greatness." He moved back to the console and made another series of adjustments to the controls.

"I'd appreciate a great burger."

The Doctor sighed. "Ace," he pleaded, "please try to listen to parts of your body other than your stomach."

"But it's the loudest part."

The column of translucent tubes that plunged through the centre of the console began to rise and fall and a familiar groaning, wheezing sound filled the air. The Doctor touched a control and the TARDIS shuddered. The wheezing sound rose in pitch and reached a crescendo and then, as the room shook for a final time and became still, abruptly stopped.

"Beyond these doors," said the Doctor, "history is happening." He stalked over to the hatstand in the corner of the room and took a cream-coloured jacket from its hook, shrugged into it and then plucked an off-white Panama hat from the top of the stand.

"Lunch," pointed out Ace as the Doctor settled the hat onto his head and stepped towards the door, "is also part of history." Waving away her comments with a motion of the hand the Doctor pulled the door open.

"Behold Tsaritsyn!" he cried, stepping through the door, "Jewel of the southern Russian-"

He emerged into a field of rubble scattered across a barren concrete wasteland, laying sullen and still under a low roof of slate-coloured cloud. The TARDIS sat on a city street in front of the shattered ruin of an apartment block. Similarly broken buildings lay as far as the eye could see in all directions, some smashed down into mere stumps of pitted concrete and twisted metal, all surrounded by fields of loose bricks and jagged masonry so that they seemed to emerge like giant's fingers through a grey sea of rubble.

"-Empire. . ." concluded the Doctor weakly. He turned in a slow circle and took in the view to the crumbling horizon. "Ah."

I'd hate to see the crummy parts, thought Ace, emerging from the TARDIS and standing beside him. The morning air was freezing and she hastened to zip up her jacket, shivering, though the Doctor seemed not to notice the cold.

"Slight miscalculation," admitted the Doctor.

"This isn't Tsaritsyn then?"

"No," murmured the Doctor, "it's Tsaritsyn alright. But I was aiming for 1842. This is more like-" He paused and looked up, listening, and for the first time Ace became aware of the distant high-pitched whistling of artillery shells in flight and the low rumbling sounds that signified their impact further off in the city. "More like 1942," said the Doctor quietly.

"Three out of four isn't bad Professor," said Ace. She shivered and tried to shrink deeper into her jacket to escape the cold air.

"And by 1942 it wasn't called Tsaritsyn anymore," continued the Doctor, strolling thoughtfully forward and picking his way around the larger pieces of rubble like a man avoiding puddles. "It had a new name by then." He frowned. "Stalingrad." He spat the name out like a curse.

"I think we did something about that in history at school," said Ace. "It was a battle, wasn't it?"

"Battle?" snorted the Doctor. "Battle is too small a word for it. No, this. . . this was a war within a war." He nodded towards the horizon. "Over there, on the banks of the Volga, two mighty armies are meeting, and their struggle will decide the destiny of a whole planet. More Soviet soldiers were killed here, in this one city, in this one bitter winter, than the British and Americans lost in the entire war. Over half a million of them, and nearly as many Germans." His voice sounded distant, as if he were talking to himself.

"Well," said Ace, "Are we going to take a look around?" She surveyed the view around them without enthusiasm.

"Not today," said the Doctor, snapping out of his morbid reverie. He turned back towards the TARDIS, grasping Ace's arm as he passed her and pulling her along. "Time we were leaving."

"But you said you wanted us to see history happen. This is history, isn't it?"

"Not the kind that should be witnessed," replied the Doctor grimly. "This is no place-" He stopped abruptly and cocked his head back as if sniffing the air, his body suddenly tensed.

"Get down!" yelled the Doctor. He put out an arm and pushed Ace bodily to the floor, jumping to one side as he did so. Taken by surprise, Ace barely had time to put out her arms to cushion her impact and she fell heavily onto the rough carpet of rubble face down.

She had barely registered the sudden pain of scrapes and grazes on her palms and forearms when the building behind them exploded in a fountain of masonry and dust that blossomed violently outward from the impact point. Larger chunks of concrete, blasted free of the building, fell all around her in a shower of debris. The shock wave of the explosion slammed Ace flat against the floor and pushed the air from her lungs as if she had been punched. Her ears rang in a high-pitched tone and the crashing sounds of the building falling in upon itself reached her only as a series of dull thumps.

When she was able to draw breath again she choked on the cloying clouds of dust that swirled around her like ocean currents. The thick grey banks of dust filled the air until it slowly began to drift and settle, covering everything with a film of grit. Ace shook her head, blinking away the dust in her eyes and coughing again. She pushed herself up into a sitting position and looked numbly around. The building that the TARDIS had materialised in front of, already pitted and gouged, had collapsed completely as if struck by some giant fist. Here and there metal girders and heavy concrete beams poked out of the rubble like bones.

All around Ace smaller pieces of brick and stone, blasted high into the air by the explosion, pattered lightly to earth. She opened her mouth wide and made extravagant yawning motions in an effort to regain her hearing as she rose slowly to her feet. The first thing that she noticed was the blue light on top of the TARDIS, dull and grey under a film of dust, the only visible part of it emerging from under a cascading slope of rubble which quietly clacked and tinkled as it settled.

The second was the Doctor, lying deathly still, eyes closed, blood trickling slowly down his forehead.

CHAPTER TWO

"Professor!" cried Ace, stumbling towards him through the litter of rubble. She was still dazed from the blast and when she reached him she fell heavily to her knees at his side. He lay on his side facing towards her, perfectly still, his hat tilted askew on his head. Carefully Ace reached out a hand and put it to his face, gently turning it upwards.

"Professor!" she said again, searching for any sign of movement on his face, and then, more quietly, "Professor?" He gave no signs of having heard her. The flow of blood on his forehead had slowed to an ooze and Ace quickly traced it to a small gash just below his hairline. The flesh around the cut was swollen and dark, a bruised lump the shape of an egg rising from his forehead. Ace removed his hat and lay it beside him and then checked his head, carefully turning it to examine it from all sides, but she could see no signs of any other injuries. She leant over and put an ear to his left breast, listening for a heartbeat and then, when she felt the telltale thump-thump from deep within his chest, she shifted her head to his right breast and listened until she heard the same. The Doctor remained limp and unmoving throughout.

From above them came a whistling sound that rose in pitch as it grew louder and Ace flinched and instinctively leant across the Doctor's prone form to shield him as another shell fell fifty or so metres away, raising another fountain of debris. Further shells began to fall to earth in a succession of thunderous explosions but the focus of the barrage seemed to be shifting away from them and as the noise of the shellbursts receded Ace slowly sat up again.

"Professor? Can you hear me?" she tried again, but the Doctor remained silent and unmoving. She turned and looked over her shoulder at the TARDIS or, more accurately, at the pile of bricks and stones that covered it. The rubble seemed to have settled now and Ace noticed with dismay that several larger pieces of concrete were embedded in the slope of wreckage, laying directly across the place where the TARDIS doors would be. She dismissed her chances of shifting them clear by hand almost as soon as the possibility occurred to her and instantly began the far more worthwhile exercise of working out exactly how much Nitro-9 she would require to blast an opening. She had made a rough calculation of the number of charges she would need and had begun to consider where best to place them when a thought occurred: how much Nitro-9 had she packed? She thought back to the last time she had packed her rucksack. Six charges, she thought. No, eight. She remembered sitting in her bedroom aboard the TARDIS and packing her rucksack with four charges and then closing it and then having a think and then re-opening it and popping in a couple more (just in case) and then closing the bag and then thinking what the hell and opening it once more and putting in an extra two charges and then zipping up the bag, and taking it with her and placing it...

Placing it against the wall in the TARDIS control room, near the doors. Where it still sat.

Ace groaned and slumped inwards as if deflating. She looked down at the prone form of the Doctor, bloodied and silent, and then back at the rubble-shrouded TARDIS and the medical bay that lay within,simultaneously ten metres and a million miles away from her. Her mind raced as she tried to think of options: clear the doors by hand - can't do that on my own - clear the door with explosives - can't do that without explosives - explosives are in the TARDIS - can't get in without clearing the doors - can't do that on my own... Ace stopped and shook her head despairingly, aware that she was thinking in circles. She looked up again and took another look around at the crumbling ruin of the city. The shells had stopped falling and their last echoes were fading through the streets, but she could hear another barrage commencing further in the distance.

Can't clear the doors by hand on my own, she thought again, and then stopped. Can't clear the doors on my own. She made a decision and took another quick look around and then leant over the Doctor again.

"Professor?" she said, hoping her last hope that he might wake or stir or show some sign of life, but he remained stubbornly unconscious. "I have to go and look for help." She kept searching his face for movement. Wake up. "The TARDIS doors are blocked and I can't clear them on my own. I need to find someone to help. But," she added quickly, "I'll be right back. I'll be right back." Slowly she rose to her feet. Trickles of fine dust poured out of the creases in her jacket as she stood. She scanned the horizon, a grim expression on her face, and then looked back down at the Doctor.

"As soon as I find some help," she said quietly.

o o o

Ace began walking, heading away from the direction that the artillery barrage had taken, reasoning that she was unlikely to find anyone under the bombardment with the time or inclination to help with rubble clearance. As she walked she stopped from time to time and looked back towards the place where the Doctor lay and the rough pyramid of stone and scree that covered the TARDIS but after she had gone no more than a hundred metres she could no longer make them out amongst the waves of debris draped over the landscape. The fighting had battered this part of the city into sameness, a uniform state of devastation that made orientation impossible. Wherever she looked she saw the same grey shell-damaged buildings, the same piles of brick and stone, banked up against walls like snowdrifts, the same rubble-covered roads and pathways. Occasionally a stray shaft of light would sneak through the low cloudbase and fall upon some shattered glass or a carpet of brass shell casings, making them briefly glint and shine, but apart from these flashes of light it was dark and dim, adding to the uniformity of the view.

She had begun to worry about her ability to find her way back to the TARDIS when she finally found a landmark. She cautiously rounded the corner of one of the buildings and found herself at the edge of a large open space, some kind of town square or plaza perhaps a hundred metres across, fringed by the shells of ruined apartment blocks. In the centre of the space lay the shallow bowl of a large ornamental fountain, silent and dry but otherwise untouched by the devastation. A ring of carved stone figures with linked hands formed a circle at the centre of the piece. As she stepped forward into the centre of the square she saw that the statues were of children, all holding hands. The silent black holes of water spouts where their mouths should be gave the figures a surprised look, as if they had just noticed what had happened to the rest of the city. On the other side of the fountain to Ace sat the blackened hulk of a tank. The long gun barrel that protruded from the turret lay drooped towards the ground in a gesture of submission to its fate and faint traces of black smoke spiralled slowly upwards from open hatches in its top and sides. The caterpillar tracks on the side facing Ace had come away from their wheels and lay draped on the ground behind it in a line of segmented metal like a drunk shedding his clothes as he staggers towards bed.

The wall of buildings that lined the square were mostly three- or four- storeys tall and beyond them Ace could see the tops of far larger structures. The slim shapes of giant smoke stacks poked up over the horizon, pale with distance. They were grouped around a concentration of huge shed-like buildings of which Ace could only see the very tops. At first glance the roofs of the giant shapes seemed undamaged but as Ace looked closer she saw the same rough-edged holes and jagged wounds that marred all of the other buildings she'd seen.

Some sort of factory district? thought Ace. Maybe she could find tools there, perhaps a crowbar she could use to lever the larger pieces of rubble away from the TARDIS doors. Maybe there would still be some civilians there, factory workers, people who might be willing to help her. She looked around the empty square again, past the smoking ruin of the abandoned tank and into the empty doorways and windows of the encircling buildings and then turned her gaze back in the direction from which she had come, searching out a path back through the silent streets towards the clutch of ruins where the Doctor lay, now tiny in the distance. She tried to orient herself, mentally tracing a line from the far-off chineys and factory roofs, through the square and back towards the TARDIS. As long as she could see these tattered landmarks and line them up just so she thought she should be able to retrace her steps.

There was a sudden noise above her and she ducked down instinctively, hunching in on herself as she waited for the rumble of shellfire, but this was a different sound, a low and constant drone like the buzzing of huge insects. Looking up she saw a group of aircraft flying just under the cloud layer. She barely had time to notice the black crosses marked on their sides and the underside of their wings before they were gone again, disappearing over the horizon as swiftly as they had come. It occured to Ace how exposed she was there in the centre of that huge open space and she hurried away from the fountain back towards the edge of the square, feeling suddenly vulnerable. She made her way up to the front of the nearest building and crouched down there next to a low bank of rubble. She shivered. Her hands were starting to go numb and she rubbed them briskly together trying to generate some heat before jamming them deep into the pockets of her jacket. In the cold air her breath curled out in front of her in long plumes of condensation and she sat there for a moment, wreathed in clouds.

She looked up at the blank canvas of the sky, waiting for more aircraft or the thunder of artillery but for the moment the air was still. Time to go, she thought and reluctantly stood, still slightly hunched. She had settled on the road out of the square that seemed to lead most directly towards the factories in the distance and had taken the first steps towards it when she heard a noise that stopped her dead in her tracks.

"Hello," said a voice behind her.

CHAPTER THREE

The Doctor's eyes fluttered and blinked as he stirred back to consciousness. Finding himself flat on the floor he made as if to sit up and then stopped and fell back, clutching at his head. He remained like that for a few seconds and then, groaning quietly, he levered himself up into a sitting position with his elbows and put out a hand to carefully examine the front of his head, touching the area around the throbbing pain at his hairline and feeling the edge of the swell of bruised flesh. When he brought his hand away from the wound he saw blood and in his dazed state it took him some time to make the connection between the pain in his head and the red-black smears on his fingers.

He looked at the ground around him distractedly and, noticing his hat lying next to him he reached out and put it on, wincing slightly at the stab of pain where it touched the cut on his forehead. Still moving slowly, he reached into a coat pocket and drew out a handkerchief and looked blankly at it for a moment before dabbing it cautiously at his head, wiping away the streaks of congealing blood before folding it carefully and replacing it in his pocket.

He tentatively shook his head and blinked several times, regaining his focus. He looked blankly at the fields of debris around him without seeming to register them, until his eyes alighted on the familiar shape of the blue light on top of the TARDIS, nearly hidden by the slope of rubble that cascaded around it and hid the rest of the blue box from sight.

He sat up straight then, suddenly fully alert, and jumped to his feet, looking around him in all directions.

"Ace?" he said quietly, still looking searchingly at the nearer piles of rubble. He turned in a complete circle, searching for any sign of her further afield, but there was nothing to be seen in any direction except grey ruins. "Ace!" he said again, louder this time, but no answer came out of the silent streets.

"ACE!"

o o o

Ace spun about, her heart pounding. She searched desperately for the source of the voice, ready to run at the slightest sign of danger.

She saw a head, wrapped about with tattered rags which all but obscured the face, poking over the top of a pile of brick fragments that lay in front of a doorway set into the side of the nearest building. Curious eyes gazed back at her from above the folds of fabric covering the face.

"Hello," said Ace, trying to sound as friendly as she could manage. The figure seemed about to reply when it suddenly stiffened, looking over Ace's shoulder with wide eyes, and then ducked back out of sight again.

Ace turned quickly and peered in the direction that the face had looked. On the far side of the square she saw the shapes of men moving cautiously through the ruins towards them. They held weapons at the ready and moved with the wariness of the hunted, checking every window and doorway that they passed. They seemed not to have seen her yet but were drawing closer with every step.

Making a quick decision, Ace turned back and clambered to the top of the rubble that the face had emerged behind. As she crested the top of the pile and put out a foot to begin descending the other side the loosely packed debris gave way beneath her and she surfed down the far side of the slope on a small avalanche of stone fragments, frantically windmilling her arms to keep her balance as she did so. As she regained her balance at the bottom of the slope she saw a small figure darting inside the nearest doorway.

"Hey! Wait!" she yelled after it, running towards the doorway herself. Stepping through the entrance she found herself in a darkened room, illuminated only by the meagre scraps of light that fell through the doorway and a single small window set into the wall next to it. As her eyes adjusted she saw the small rag-wrapped shape on the far side of the room, deep in the shadows. It seemed to wait there until she had spotted it and then turned and vanished deeper into the darkness.

"Wait up!" said Ace again, following. The far end of the room was almost completely lost in shadow but Ace could just make out a lighter patch in the gloom which as she approached became a rough-edged gap in the wall, barely wide and tall enough to admit a person. She squeezed through it and found herself in a narrow corridor on the other side of the wall. A few small holes in the ceiling admitted just enough light to make out the mysterious shrouded figure at the far end of the corridor looking back at her, then turning and disappearing again, this time down a set of steps that plunged into blackness.

Ace jogged down the corridor to stand at the top of the steps. She peered uncertainly into the space below but could make out nothing except the stairs fading from sight as they descended. She followed, placing her feet gingerly on the creaking wooden slats of the steps, straining her eyes to make out any shapes in the darkness. When she reached the bottom of the stairs her feet crunched on a light sprinkling of gravel. From quite close by she could hear the steady musical tinkle of waterdrops falling into puddles and from the echoes of this sound and from the feel of the air around her Ace sensed that the space around her was large but also totally enclosed apart from the opening at the top of the stairs. Possibly a tunnel of some kind?

"Hello?" she called hopefully into the dark. "Is there anybody there?" Faint echoes of her voice came back at her from all directions. Definitely a tunnel she thought. "I saw you upstairs, in the street," she said and then quickly added, "I just want to talk; I won't hurt you." She thought, but did not say, as long as you don't hurt me.

For long seconds there was silence, broken only by the steady drip-drip of the water falling nearby, and then there was a quiet shuffling sound and a small shape detached itself from the gloom and stepped slowly forward. It was wrapped in an ill-fitting assortment of ragged clothing and scraps of cloth wound about it like a mummy and it was only when it reached a hand to its head and drew back the rags across the lower part of its face that Ace realised that it was a small girl of perhaps nine or ten years old. Her face was covered with grime and her hair filthy and bedraggled but the eyes that looked back at Ace were bright and unblinking with curiosity.

"Hello," said Ace, forcing a smile, "What's your name?"

The girl looked back at her, head tilted to one side, frowning, as if appraising her. Eventually a shy smile replaced the frown on her face and she said "I'm Alina." She paused and then said, "Who are you?"

"My name's Ace," replied Ace. She looked around them into the darkness. "Do you live here? In the city I mean."

The girl nodded. "I live with my mother, and some other people." She raised a hand and pointed into the blackness behind her. "Not far from here."

"Alina," said Ace, "I'm here with a friend, and he's been hurt. I need some help to clear some rubble to get into our. . . ah . . . vehicle. Do you know anyone who could help me with that? Some adults?"

Alina considered this. "Peter might be able to help. Where is your friend?"

"Near here," said Ace, "But he's all alone and I need to get back to him soon. These others - are they close?"

The girl nodded. "Come with me," she said, "I'll take you to them." She turned and began to walk into the darkness, away from the small patch of light at the bottom of the stairs, beckoning Ace to come after her. Picking her way carefully, Ace followed, trying to keep sight of the girl's shape in the pitch-black of the tunnel.

"Follow me," whispered Alina, "And be quiet."

"Do the soldiers come down here?" whispered back Ace. She was only barely able to make out Alina's head shaking from side to side in reply.

"Not any more," said the girl quietly, pressing on into the darkness ahead, "But we have to keep an eye out for the Baba Yaga."

o o o

"Ace!" The Doctor cupped his hands to his mouth and shouted the name into the empty streets. He walked down the middle of the road, picking a path around the mounds of rubble and detritus that littered it, peering intently down every side street and alley, into every window and doorway, looking for any sign of his companion. From time to time volleys of artillery fell to earth nearby, some less than a hundred metres from him, but he barely seemed to notice them. He spun about as he walked, shouting her name in all directions and listening intently for any reply but he saw nothing except the ruined city and heard nothing but the thunder of the exploding shells and the rumble of collapsing buildings that followed in their wake.

Eventually he came to a large open area with some sort of ornamental fountain at its centre, ringed by more battered buildings. The shell of an abandoned tank lay on the other side of the fountain, still smouldering. The Doctor walked briskly towards the centre of the square and stopped twenty metres from the fountain. He looked up, over the tops of the buildings lining the square, and peered thoughtfully at the distant shapes of factories and smoke stacks on the horizon.

He was still looking at them when the grey-clad soldier rose up from his hiding place behind the stone bowl of the fountain, and raised his rifle to his shoulder, and fired.

CHAPTER FOUR

After only a few minutes following Alina through the tunnels Ace realised she was completely lost. The girl had led them in near silence through a succession of twists and turns in what Ace was still trying to think of as just a system of tunnels, largely because she was trying to avoid thinking of the word sewer. From time to time they passed through a section lit by shafts of pale light, spearing through cracks in the ceiling and turning the shallow puddles of dirty water on the tunnel floor into shimmering mirrors, but for the most part they walked in perfect darkness, led with unerring confidence by Alina. In a few sections the puddles were deeper and they splashed as quietly as they could manage through freezing calf-high troughs of filthy black water. In other parts the water was deeper still, almost waist high, and they had to crawl on hands and knees along a narrow concrete shelf that lined the side of the tunnel just above the water level.

Occasionally when they reached a junction where the tunnel branched out into others Alina would stop and crouch and listen and several times in the darkness Ace nearly walked into the back of her before the girl, apparently satisfied that they were still alone, rose up and led her onwards.

After perhaps five minutes of this they came to another of the water-filled sections and Ace followed Alina as she climbed up onto the hard concrete shelf and shuffled slowly along it. Further down the tunnel, ahead of them, Ace could make out a column of grey light falling through a heavy metal grille set into the roof. As they drew nearer to the patch of light Ace noticed the water underneath the grille, dirty and brown and still. Mottled patches of scum floated on the dully glistening surface and, as she watched, they began to bob gently as the surface of the water undulated and rippled. Ahead of her, Alina seemed to have noticed this as well. She stopped crawling and looked at the bobbing surface of the water and then turned to look ahead of them again, into the blackness at the far end of the tunnel. She knelt there on the shelf on hands and knees, frozen still, and then very slowly began to lie flat, crouching down and pressing herself as close to the side of the tunnel as she could. She looked quickly back over her shoulder at Ace and whispered, almost too quietly to hear, "Lie down and cover your face until she's passed. Don't look up until I tell you."

"What is it?" whispered back Ace. She risked a quick look down the tunnel past Alina but could see nothing. The water visible underneath the grille in the ceiling was beginning to peak and trough in slow rippling motions now and for the first time Ace heard the distant slosh-slosh-slosh of something moving through the water ahead of them, and getting closer.

Alina looked back over her shoulder again. "It's the Baba Yaga," she hissed. "She's here."

o o o

The echoes of the shot rang around the desolate square as the soldier worked the bolt of his rifle to chamber another round with a sharp click-clack. Another half dozen or so soldiers in dirty grey German Army winter smocks rose from behind the fountain, weapons raised and pointing at the Doctor, who had not moved since the shot had whistled past his head. They came out from behind the low stone wall and fanned out around him.

"Hands in the air!" said one of the soldiers, stepping forwards and gesturing upwards with the barrel of his submachinegun. "Don't move!"

The Doctor drew himself up to his full height and regarded the men before him with a withering gaze. "Who is in command here?" he demanded loudly.

"I said, hands in the air!" said the soldier with the submachinegun again. As he did so the Doctor caught him sending a swift glance at another of the men. We have a winner, thought the Doctor, and turned away from the speaker towards the man he had looked at. "You!" he said, looking the man insolently in the eye, "Identify yourself." He spoke with such assurance that one or two of the men around him began to send questioning looks at each other.

The man the Doctor had addressed stepped forward. His submachinegun was still pointed towards the doctor but was no longer aimed quite so deliberately at him as it had been a moment ago. He looked uncertain and the Doctor noticed that he seemed somewhat younger and cleaner than the other men, his uniform less stained and ragged and his face less lined and drawn. He looked the Doctor up and down, puzzled. "Who are you?" he said.

"New at the front-" He flicked his eyes at the epaulettes of the man's jacket, "-Leutnant?"

The officer's mouth opened as if to say something and then closed again. Around him the Doctor sensed the muzzles of the guns trained upon him wavering though not, he noticed, that of the first speaker, who still held his weapon aimed steadily at him.

"You obviously haven't been at the front long enough," continued the Doctor acidly, "to recognise a member of German Intelligence when you see one." His eyes narrowed and he regarded the officer with a look that dripped contempt. The man seemed to shrink back from his gaze. He looked briefly at the faces of his men, as if for support, and then down at the floor before meeting the Doctor's eyes again.

"Well - uh - sir. . ." he began, and around him the Doctor sensed the gunbarrels lowering.

"Never mind, Leutnant," said the Doctor, loading the word Leutnant with what he hoped was sufficient disdain to convey the distaste of a man unused to addressing such lowly ranks. "We'll let it go - this time." He looked around at the rest of the men, most of whom were busy redirecting their weapons towards the surrounding buildings. Only the man who had spoken first still pointed his weapon anywhere near the Doctor, and even he was no longer aiming directly at him. "What is your mission?" demanded the Doctor, turning back to the officer. "Leutnant. . .?"

"Leutnant Albers, sir," said the officer. "We're searching the area for a Soviet saboteur. They've been cutting our communication lines in this sector, stealing telephone wires. . . a patrol went out yesterday but they haven't been heard from since." Albers paused, then said, "May I ask what your mission is here sir?"

"My mission?" snapped the Doctor. "Classified, Leutnant Albers, that's what my mission is. If you don't like it you may take it up with my superior."

"Oberst Rohm you mean, sir?" By way of reply the Doctor simply raised one hand and pointed upwards.

"You mean. . . General Pfeiffer?" asked Albers, but the Doctor merely shook his head and pointed upwards again.

"General Von Paulus?" said the Leutnant incredulously, and this time the Doctor merely looked up and nodded his eyebrows skywards. Albers' eyes were wide and he gulped as he said, "You can't mean. . .?"

"That is exactly who I mean, Leutnant Albers," said the Doctor icily, "and you would do well to remember it."

"Yes sir," replied Albers.

"My mission here supercedes your own Leutnant," said the Doctor, "You will place yourself and your men at my disposal. Do you understand?"

"Yes sir," said Albers again. "What do you need us to do?"

The Doctor frowned. "I have become separated from my companion. I need your help to find her."

"Her, sir? Your companion is a woman?"

"A girl," said the Doctor. "We split up a few minutes ago. She must be somewhere nearby."

"If she's here then we'll find her sir," said Albers. "Description?"

The Doctor thought about this. "Description?" he said at last. "Hmm. Well, let's see: she's willful, rebellious, infuriating, obstreporous, impulsive, wayward, headstrong, exasperating, delinquent. . ." He paused and took a step closer to the officer. ". . . and if you or your men allow a single hair on her head to be harmed," he continued quietly, staring into the man's eyes, "I will bring the world down around your ears."

o o o

Pressing herself hard against the cold damp concrete of the tunnel wall, Ace shivered. The ledge that they lay on was only just wide enough for them to lie flat on and she was uncomfortably aware of the deepening waves rippling across the surface of the water just below the edge of the shelf as whatever was approaching them drew closer. The long slow whooshes of displaced water that marked its strides through the waist-high water echoed down the tunnel towards them, louder with every second.

Ace raised her head for an instant and then quickly ducked her head back down again. There was still nothing to be seen in the tunnel ahead of them, even though from the noise it was making and the path of disturbance in the water the figure approaching them must have been almost under the patch of gridded light that fell through the grille in the roof above. Lying in front of her on the shelf, perfectly still and pressed hard up against the side of the tunnel wall, Alina resembled a bundle of rags in the darkness.

A sudden icy cold touched Ace's side as the undulating water lapped over the edge of the shelf and she had to fight to restrain a gasp as the freezing wave flowed around her. The splashing sounds were only a few metres away from her now and she closed her eyes tightly shut and put her head flat against the wet concrete, her forehead pushed into the angle of wall and shelf. Every slow dragging step that the approaching figure took through the water sent another freezing tide lapping around her until her whole front was soaked through. The sound of the steps was almost next to them now, coming on in the darkness with metronomic regularity. Slosh-slosh-slosh-slosh-

And then the steps were directly alongside her, only centimetres away from her head.

And then they stopped.

CHAPTER FIVE

The Doctor jumped up onto the low wall surrounding the fountain at the centre of the square and surveyed the space around him. Leutnant Albers and his men were dispersed around the square in ones and twos, nosing into doors and windows, searching behind banks of rubble and kneeling occasionally to look for footprints in the thin frost that coated the ground.

The Doctor turned in a slow circle on the spot, careful to keep his balance on the narrow stone ledge of the fountain rim. He took in the half-demolished buildings on the edge of the plaza with all their shell damage and bullet holes and scorch marks, then raised his gaze to look at the distant rooftops of factories further to the north. As the morning wore on the war in the rest of the city seemed to have woken up; to the east and south of them volleys of shells tore through the air at irregular intervals with a sound like ripping cloth, followed by the deep booming sounds of their arrival, and the drone of aircraft flying above the low cloud base became more frequent. The faint echoes of exchanges of small arms fire from further off in the city drifted on the cold air like the strains of some violent concerto. Frowning, the Doctor tried to tune these sounds out and concentrate on the matter at hand but something was nagging at him at the back of his mind. Something about the square, about the buildings around it, something out of place; something he had missed. He scanned the facades again, making note of the scars and gashes and holes of shells and bullets and the scorches of. . .

Hopping down from the ledge of the fountain, the Doctor walked briskly towards one of the ravaged buildings, staring intently at a black burn mark scored into the concrete at just above head-height level. His frown deepening, he stood looking up at the mark thoughtfully, then looked quickly around him, searching the nearer piles of debris. Finding what he was looking for, he bounded over to a mound of rubble and broken bits of furniture and reached into it, pulling free a small wooden chair which he carried over to the front of the building and placed against the wall directly underneath the burn mark. He put both hands on the chair and pushed down on it, checking its strength before climbing up on to it and leaning against the wall and inspecting the black mark burnt into it. He dabbed his fingers gingerly at the soot-black streak then raised his fingers to his nose and sniffed them. He wrinkled his nose and then brushed his fingertips together distractedly, still staring at the burn mark.

"Directed energy weaponry, here, in 1942?" he murmured to himself. "That isn't right." He looked again around the ring of buildings circling the fountain, looking more closely now that he knew what he was looking for. Within seconds he had identified similar burn marks scarring the walls of two other buildings nearby and his frown deepened to a grimace.

"That isn't right at all."

o o o

Eyes squeezed tightly shut, Ace could feel her heart pounding through her sodden clothes against the cold concrete of the ledge. She was suddenly aware of her own breathing, her ragged breaths sounding alarmingly loud to her in the silence of the tunnel. Some animal part of her brain was aware of something standing beside her in the water, a looming presence, shapeless in the dark.

And then the silence was broken by a low rattling snarl above her, clicking and growling and echoing into the darkness.

o o o

The hunter leant over the two prone shapes lying on the ledge beside it. Their heat-shapes blazed like fires against the cold stone of the tunnel, the white and yellow heat of their body cores fading to deeper reds and blacks at the extremities. It activated a subroutine in its visor that flipped it through the electromagnetic spectrum but none of the overlaid views revealed anything of any interest to it. No weapons, no technology, just two tiny prey-animals cowering in the dark. It let out a low growl of disappointment and was gratified to see the shapes shiver and quake in response, huddling in on themselves.

It stood there a moment more and then turned away. It shifted the weight of the bulky coils of wire it carried on one shoulder and grudgingly resumed its stride, ploughing a furrow through the surface of the freezing water.

o o o

As the splashing sounds resumed and began to move further down the tunnel, away from her, Ace lifted her head from the surface of the ledge, still shivering from more than just the cold. She counted the slooshes of the creature's strides through the water as they moved away, gauging its distance. When she judged that it was approaching the junction at the far end of the tunnel she risked raising her head and looking back the way they had come, towards the receding sound of the creature's passage. At first she saw nothing but the telltale furrows of disturbed water but then, just for an instant, there was a rippling pattern in space, a momentary glimpse of a giant figure that flickered into and out of existence. Fine traceries of blue light crackled and sparked around its flanks where they met the black surface of the water, and then it turned the corner and was gone, swallowed up by the darkness.

Ace was suddenly aware that she had been holding her breath and let out a long exhalation. Still shaking, she pushed herself back up onto her hands and knees. Ahead of her she saw Alina do likewise. The girl looked back over her shoulder at Ace, her expression seemingly unperturbed.

"Come on," she whispered back at Ace. "It isn't far now". She started to resume her shuffling march along the shelf when Ace reached out a hand and put it around her ankle to stop her. Alina turned again and looked questioningly back at her.

"What was that thing?" hissed Ace, shooting a glance back down the tunnel to the point where the figure had disappeared. Alina shrugged.

"The Baba Yaga," she replied, as if this was obvious. "She's gathering materials for her nest. Now come on. We're nearly there." She began to crawl forward again.

Ace took another look back down the passage behind them. The splashing sounds were only faint echoes in the distance now and the surface of the water was settling again as the ripples died away, becoming flat and still once more.

o o o

The Doctor was leaning in close examining one of the burnmarks on the wall when he heard footsteps approaching and then coming to a stop a few metres behind him. "No sign of her here sir," said the Leutnant's voice, almost apologetically. The Doctor turned to face him, his eyes narrowing thoughtfully.

"Well, never mind," he said. "Tell me about the fighting in this sector, Leutnant. Anything. . . unusual taking place?"

"Sir?" said Albers, puzzled. "I thought the search for your companion-"

"Is of overriding importance, yes," interrupted the Doctor. He turned back to look again at the burn mark on the wall. "But if I'm right," he continued, "there may be more at stake here than one girl's life." He spun back to face Albers. "Come on Leutnant, out with it now! Any unusual activity, events, sightings, disappearances. . . anything at all."

"Unusual, sir?" Albers thought about it. "Well," he said eventually, "I suppose the Ivans stealing our telephone wires is a bit. . . odd."

"Stealing your telephone lines you say?" said the Doctor. "Not just cutting them?"

"No sir," said Albers. "That's what we were sent out here for. To look for-"

"Yes yes," interrupted the Doctor again, testily, "So you said earlier. And it's only happening in this sector - not anywhere else?"

"As far as I know sir." Albers raised an arm and pointed towards a group of ruins just barely visible in the distance to the west. "It was first reported a few weeks ago, in the area around the tractor factory, but it stopped after we called in an artillery bombardment and destroyed the factory. Then a few days later it started happening around this area." He indicated the area around the plaza with a broad sweep of his hand. "Is it important sir?"

"It might be, Leutnant," mused the Doctor. "It just might be." He looked back towards the ruins on the horizon that Albers had pointed out. "You say the thefts stopped after you shelled the tractor factory?"

"Yes sir."

"And the factory was destroyed?"

"Almost completely sir. It's just rubble now."

The Doctor nodded slowly, thinking about this.

"Almost completely you say?" he said eventually. He looked again at the distant ruins.

"Show me."

CHAPTER SIX

"This way," hissed Alina. She stopped at the end of the tunnel and turned back towards Ace, beckoning her onwards. Their meeting with the creature was more than a hundred metres and several turns in the tunnel behind them now but every so often Ace still found herself turning and staring into the dark behind her, her ears straining to hear any sound beyond the tinkling of dripping water and the fainter rumbling echoes of the fighting above that reverberated through the very foundations of the city.

"Come on," called out Alina again, waving Ace towards her. She stood at a rough-edged gap in the side of the tunnel wall, covered by a tattered canvas sheet hung across it on the other side of the hole. As Ace caught up with her guide she noticed what looked at first like unlit torches hung on the wall on either side of the covered opening. When Alina drew back the covering and ducked through it the muted flash of light from within showed that what she had taken to be torches were the remains of broken rifles, collections of snapped and splintered wood and bent steel tubes bound together into bundles with lengths of twine.

Alina stood on the other side of the opening, holding the flap of material open and impatiently looking back at Ace, waiting for her to follow. When she saw Ace paused on the other side she followed her gaze and saw her looking at the broken weapons.

"What are these?" asked Ace.

"Totems," replied the girl, "To ward off the Baba Yaga." She ducked quickly back out of the hole into the tunnel beside Ace and took a look down the length of the tunnel in both directions. "Peter made them. He'll explain everything. Now come on." And with that she lifted the canvas flap and ushered Ace through the opening ahead of her.

Stooping, Ace stepped through the hole. She was struck at once by the warmth inside after the cold and damp of the tunnels. Looking around she saw that they were in a small concrete-walled room, perhaps six metres to a side. The ceiling above was low and slightly vaulted and the top of her head brushed against it when she stood upright. Apart from the opening they had entered through that led into the tunnels there were two other doors in the walls leading out of the room, both covered by the same makeshift fabric flaps. Around the edges of the room lay a number of filthy mattresses, a small table and a number of battered and mismatched chairs. In one corner sat the source of the dim light, an ancient-looking black iron stove, flickering red and orange through a small grate in the front. Huddled around it in a semi circle on the floor sat three small figures wearing the same loose assortment of filthy-looking rags as Alina. They sat facing the glowing stove, their rag-wrapped hands held out before them towards its warmth. Two of them turned their heads to look when they heard Alina and Ace step into the room, acknowledging Alina with nods and smiles and curiously looking Ace up and down before turning back towards the warmth. The third, slightly larger figure in the middle of the trio seemed not to notice their entrance and remained facing the glow of the stove.

Alina walked into the room with the familiarity of a long term occupant, removing her outer layers of ragged garments with practiced movements and dropping them onto one of the mattresses. With every grimy grey layer that she peeled off she seemed to shrink (like one of those Russian dolls thought Ace) until at last she shrugged herself free of an outsized khaki tunic and stood before Ace in a stained and patched dress of indeterminate colour and a cardigan in which the war between wool and holes stood poised on the verge of a decisive victory for the holes. Underneath her layers of clothing she was a tiny, stick-like figure. Her dirt-mottled skin was stretched over the frame of her bones as tight as a glove and her elbows and knees bulged out alarmingly, making her arms and legs look like snakes that had swallowed tennis balls.

"This is home," she said, putting out her arms to indicate the rest of the room. She walked over to the trio of figures grouped around the stove in the corner.

"These two," she said, pointing to the two smaller figures sat either side of the larger one, "Are Stepan and Mykola." At the sound of their names the two turned their heads and gave brief shy smiles, revealing the faces of boys no older than Alina, both similarly dirty and malnourished.

"And this," said Alina, moving directly behind the figure seated in the middle, "Is Mama." She put out her hands and with gentle movements slowly eased back the ragged cloth hood shrouding the silent figure's head, uncovering a shock of bone-white hair. "Mama?" said Alina quietly. "Mama, we have a guest." Ace stepped around the side of the huddled trio to face them and introduce herself but as the seated woman's face came into view the words died in her mouth.

Her first thought was that the old woman was dead, propped up into a sitting position only by the two boys sat on either side, holding her up like bookends on a shelf. Her features had a stillness, a lack of animation that Ace had only ever seen before on the faces of the dead. The eyes were open but lifeless, glazed over like two marbles sunk into a mask. Her whole face was lined and etched with deep furrows, ringing her features like the contour lines of some desolate hillside, lines that were thrown into sharp relief by the warm flickering light of the stove before her. It was only when she slowly blinked her eyes that the illusion of death passed and Ace's initial sense of horror was replaced by a wave of pity. Unbidden, the word catatonic came to mind, and Ace wondered what sights the woman had witnessed to drive her so deeply back inside herself.

"Mama's not well," said Alina, "But she's getting better." The girl spoke defensively enough that Ace guiltily wondered how much her own face was betraying her feelings and she hurriedly forced her features into what she hoped was a reassuring smile.

"Please, sit," said Alina, motioning at Ace to take a place in front of the stove beside the others. "I'll make tea." She went over to the side of the stove and retrieved a soot-black teapot which she proceeded to fill with water from a jug. She strained to lift the newly filled vessel onto the top of the stove and then stepped over to one of the small piles of possessions stacked neatly around the edges of the room and returned bearing a mis-matched assortment of cups.

Ace took a place by the side of the others in front of the stove and sat down. As Alina busied herself making the tea she took another look around the room, noting for the first time the care with which the group's meagre belongings were arranged. This is everything, she thought bleakly. This is all they have in the world. She tried to imagine what their lives must be like, scraping out a life amongst the ruins, abandoning hearth and home for the precarious sanctuary of the tunnels and cellars below, huddling in the darkness while above them two faceless mechanised leviathans wrestled and fought and battered the city to destruction in their efforts to claim it for themselves.

Just then the canvas flap covering the entrance to the tunnels was thrown back and a young man ducked quickly through it and into the room. He dropped a small grey sack at his feet, pulled back his hood and seemed to be about to say something when he noticed Ace sitting with the others.

"Hello Peter," said Alina over her shoulder, still tending the teapot on the stove, "This is Ace." She nodded her head briefly in Ace's direction and Ace, in turn, nodded a greeting to the newcomer. "Her friend has been hurt and she needs our help," continued the girl, matter-of-factly.

"Oh," said Peter, looking uncertainly from Ace to Alina and then back again. "Well then. . . how can we help you?"

Just like that, thought Ace, wonderingly. They lose everything, their homes are destroyed, they get driven into the sewers like rats, and then one day a stranger wanders in and asks for help and they say yes, just like that. "I just need help clearing some rubble from my vehicle," said Ace. "It should only take a few people, and maybe some tools." She looked around the room. "How many of you are there?"

Peter took off the tattered grey greatcoat that he wore, bent to pick up the sack that he had dropped and then deposited both on one of the mattresses around the edge of the room. He walked to Ace's side and sat beside her. He was, Ace thought, about the same age as herself or perhaps a couple of years older, but like Alina he was painfully thin, as if some sculptor had whittled off all of the excess flesh from his frame until only the bare bones remained.

"There's just the five of us I'm afraid," said Peter, waving a hand in the direction of the others. "How much rubble are we talking about?"

More than we can shift, thought Ace grimly, looking at the bony figures sat around her. "Quite a lot," she admitted. "And there are some concrete beams in it too. Big ones." She shook her head. "I don't think we could manage it with just us. If I only had some explosives. . ."

"Explosives?" said Peter. He gave a small smile. "Now there we can help."

"You've got some here?" said Ace hopefully, looking around the room again.

"Well, not here," said Peter, following her gaze, "But believe me, in this city finding something that'll blow up isn't usually a problem."

"Oh," said Ace sheepishly, remembering the ruined city above them. "Yeah. Right."

"I think there are some demolition charges in one of the abandoned factories above us," said Peter. "They were supposed to be used to blow up the production lines to stop them from falling into German hands but I suppose someone must have changed their mind because they crated up all of the machinery and sent it east instead. In the confusion most of the explosives got left behind."

"Great," said Ace. In her mind she was already planning her route back to the TARDIS but when she started to retrace the way they had come she suddenly remembered the creature in the darkness. She gave an involuntary shudder at the memory. "But what about that. . . thing, in the tunnels? What was that?"

"Thing?" said Peter, puzzled.

"We passed the Baba Yaga on the way here," called Alina over her shoulder, still busying herself at the stove.

"Oh, don't mind her" said Peter. "She only attacks people with weapons. She leaves you alone as long as you stay out of her way."

"But what is she?"

"The Baba Yaga?" said Peter. He sounded surprised. "The folk story? The witch in the woods? No?" He looked at her expectantly. "Didn't your mother ever tell you stories about the Baba Yaga?"

"Mum didn't tell me many stories when I was growing up," admitted Ace. "She mainly left that to Jackanory."

"I always thought that she was just a fairy tale," said Peter. "Something that mothers tell their children to make them behave. But then a few days after we moved down here to escape the fighting she just. . . appeared. And soon after she arrived the soldiers that came into the tunnels started disappearing. And then the soldiers that came looking for those soldiers disappeared as well. And then, after a while, they stopped coming down here altogether." He motioned towards the entrance back into the tunnels. "I made those totems by the door out of some broken weapons I found in the buildings above, to show her we're not a threat. It seems to work. We see her in the tunnels occasionally but mostly she just roams the city collecting materials for her nest." He looked up as Alina approached them, carefully carrying two chipped and faded mugs.

"Her nest?" said Ace. "Where's that?"

"Through that door," said Alina, nodding towards one of the other entrances to the room. "Up the stairs and turn left. You can't miss it." She smiled politely as she held out one of the steaming cups towards Ace. "Tea?"

CHAPTER SEVEN

The buildings on either side of the road had been almost completely levelled and the patrol picked their way across the resulting fields of rubble with care, advancing tactically in small groups, ducking for cover in every hollow and crouching behind every low mound and the few remaining fragments of walls still standing. The barrels of their guns tracked the ruins ahead of them, covering suspicious shapes and patches of shadow. Fingers twitched fearfully on triggers at every sound as they approached their objective, the charred skeleton of the factory that dominated the skyline half a kilometre ahead of them, dwarfing the lesser ruins around it.

The Doctor strode briskly yet casually down the middle of the road, occasionally emitting a cheery burst of whistling and looking for all the world as if he were sampling the morning air before deciding where to eat lunch. If he noticed the anxiety of the men scrambling across the low dunes of brick and stone on either side of him he gave no sign.

Leutnant Albers, advancing across the rubble amongst his men, found his attention uncomfortably split between monitoring his squad's tactical manoeuvring towards their target on the one hand and keeping an increasingly incredulous eye on his new commander on the other. He looked on with horror as the Doctor walked unconcernedly down the middle of the road, completely exposed on all sides, and he winced visibly every time the Doctor loudly hummed another snatch of opera or gave a jaunty whistle. As they drew closer to the shell of the factory ahead Albers began to angle his advance inward towards the road to bring him closer to the Doctor's path. When he had worked his way to the edges of the rubble lining the street along which the Doctor strode he called out to him in a low voice.

"Uh. . . sir?" he said quietly, then, louder, "Sir?" The Doctor halted and looked over at Albers, crouched low by the edge of the street, as if noticing him for the first time.

"Yes Leutnant, what is it?" called out the Doctor, loudly enough to make Albers wince again.

"This area is supposed to have been cleared of the enemy, but there may still be snipers in the area sir," hissed back Albers .

"Oh, quite possibly Leutnant," replied the Doctor airily, as if discussing the possibility of rain later, "but it would take someone with a heart of stone to shoot a man wearing a Panama hat in a warzone, don't you think?" He turned to look towards the hulking remnant of the factory ahead of them, nodded in its direction and then turned back to Albers and asked "Is that the place?"

Albers nodded. "Yes sir."

"Splendid," replied the Doctor. "Why don't you and your men wait here while I take a look, Leutnant? This shouldn't take long." And with that he strode purposefully onward towards the ruin.

Shaking his head, Albers gave a low whistle to attract the attention of the senior noncoms leading the advance across the rubble. When he saw them looking questioningly towards him he made the hand signal for patrol halt and then the signal for hold your positions. He watched as his men settled into all-around defensive formations, the groups on either side of the road forming into rough circles, covering all sides with their weapons, before he rose from the roadside and trotted forwards after the Doctor.

The smashed remains of the huge structure before them formed a low hill of jagged rock, crowned by rusted iron beams and girders poking out through the rubble like the ribs of some great metal beast. The Doctor walked up to the edge of the banked debris that lapped out beyond the original foundations like a fossilised tide and began to clamber up the slope. Albers, following twenty metres behind him, watched as he scrambled and climbed his way up the incline, dislodging small avalanches of loose brick and scree with every step. When he was less than halfway up the mound he stopped and leant forward, inspecting a small hollow in the hillside. He bent forward and poked his head into the gap and then, as Albers watched, slowly crawled into the gap in the rubble face and, with a final wiggle of his legs as he shimmied into the hole, disappeared into the mound.

Albers approached the edge of the mound cautiously, throwing glances left and right, the muzzle of his submachinegun following the movement of his eyes. He took a number of careful steps onto the lower slope of the concrete hill, steadying himself as the top layer of loose bricks and fragments of stone gave way under his feet. He looked up at the spot where the Doctor had burrowed his way into the face of the hill but there was no sign of him. He took a quick look back towards the positions where the rest of the patrol lay waiting and then a longer look around the area beyond. When he saw no signs of movement he turned back and began to pick his way up the hill. As he approached the site of the Doctor's disappearance he thought that he heard a sound and stopped to listen, ears straining to tune out the constant low rumble of artillery from the horizon. Eventually he was able to make out a faint sound of shifting rubble, a distant clinking and clacking of dislodged bricks that seemed to be coming from somewhere within the mound itself. Stooping and turning his head to one side, he leant close to the surface and listened. Almost as soon as he did so there was a sudden clatter of bricks as the Doctor's head emerged from the rubble ten metres further up the slope, poking out of the ground like some furtive mammal emerging from its burrow and sniffing the air. As his arms and chest rose out of the ruins Albers saw that he was running a length of wire through his hands, pulling it out of the depths from its source within the heart of the mound. After a few seconds of this the line went taut in his hands, caught on some unseen obstruction below, and the Doctor disappeared back into the ground, muttering to himself.

Albers scrambled up the slope towards the spot but by the time he got there all he found was the carelessly spooled length of wire. He peered into the gap from which the Doctor had appeared but all he could see was blackness. From within Albers could hear more far-off sounds of movement and then a loud "Ow!" followed by a series of angry exclamations. Moments later the Doctor's head burst out through the surface of the rubble again, this time emerging at a spot near the top of the pile amongst the tangle of metal beams. As before, he was tugging a length of wire free of the ruins. Albers quickly climbed up the slope and reached the Doctor just as he pulled the end of the wire out of the ground with a triumphant "Ah ha!" Still half submerged in the rubble, he brought the frayed and twisted end of the cable up to his face and inspected it closely, picking apart each individual strand and examining them one by one.

"Ah, Leutnant," said the Doctor without looking up from the wire, "There you are." He thrust the ragged end towards the young officer. "Here," he said. "From the looks of it I should say this was attached to some kind of pulse modulator." When Albers took the cable from him the Doctor levered himself up out of his hole, stood and then vigourously dusted himself down with both hands.

"It seems as if whoever is stealing your phone lines was trying to use them to build some sort of hyper-spectral alpha wave transmitter," said the Doctor. He pointed up at the metal girders that poked out of the mound all around them. "I imagine that before the building was destroyed the lines were used to attach the pulse modulator to the factory's steel frame, turning the whole building into a huge transmitter." He brushed his hands together, removing the last traces of dust from them. "Quite clever, really," he said, grudgingly.

Albers' face creased in confusion. "Sorry sir, but. . . a hyper. . .structural. . .?"

"A hyper-spectral alpha wave transmitter," corrected the Doctor. He looked at Albers for any sign of understanding but the Leutnant's features seemed if anything to be more confused than before.

"An interstellar particle wave beacon," said the Doctor slowly, as if this explained everything but Albers looked back at him blankly. The Doctor rolled his eyes and sighed loudly.

"A big radio," he said crossly and was rewarded by the sight of Albers' face lighting up with comprehension.

"I see," said Albers. He looked at the frayed twists of wire in his hand and then up at the girders above. "So you think this was one of Ivan's main communications hubs then sir? Do you think they were trying to contact Moscow?"

"Moscow?" said the Doctor, looking briefly amused. "No Leutnant, I don't think they were trying to reach Moscow." The smile left his face. He craned his neck and looked up at the blank wall of grey-white cloud hiding the sky above them.

"I think they may have been a little more ambitious than that."

CHAPTER EIGHT

"When we get up there stay close to me and keep quiet," whispered Peter. "If the Baba Yaga appears then just follow my lead and try not to make any sudden movements. Understood?" The darkness in the stairwell was almost total but Ace was just able to make out Peter's outline as he spoke, a patch of lighter grey against the black.

"Got it," she replied, as quietly as she could. She saw Peter's outline move and heard the faint scuffing of his feet as he climbed the last few steps towards the almost invisibly faint glow of light seeping around the edges of the door at the top of the flight. They had left their makeshift home five minutes earlier through one of the canvas-covered doorways, leaving Alina's mother with the two smaller boys. When Ace had pointed out to Alina that the door they were using was the same one that led to the Baba Yaga's nest the girl had looked at her as if she were stupid and said "Yes, if you go left at the top; we're going to go right. We have to go past her nest to get to the factory that Peter told you about but we're not going to go in." The doorway had led them into a short length of pitch-black corridor leading to a short flight of stairs, and then another slightly longer stretch of corridor, dotted along its length with the open doors of low-ceilinged storerooms and reeking of some acrid industrial chemical and then finally to the stairwell where they now sat waiting for Peter to call down to them that it was safe to ascend.

There was a sudden flare of light from the top of the stairs as Peter eased the door open a crack. In the wash of pale daylight that spilled through the gap Ace could make out Peter's face cautiously nosing up to the doorframe and peering intently out. After a few seconds he extended a hand towards Ace and Alina and waved at them to come up and they padded up the steps as quietly as they could until they crouched alongside Peter by the door. Through the crack of the opening Ace could only see a thin sliver of concrete and pale grey sky. She could hear the faint booming of guns in the distance but the street outside seemed quiet. Slowly, Peter rose from his crouch and pulled the door open and then stepped through it. Ace slipped through the doorway after him and found herself emerging from a low brick building that sat alone in the middle of a wide stretch of concrete apron separating two huge structures standing seven or eight storeys tall on either side. Peter led them towards the building on the right at a crouching run, occasionally sending nervous darting glances over his shoulder at the building on the other side of the concrete strip. There was an open doorway set into the wall ahead of them about halfway along its length and Ace and Alina followed Peter up to it. He paused on the threshold for a moment, poking his head in and peering to both sides before stepping inside.

Ace followed Peter through the doorway and found herself in a room that seemed scarcely smaller than the outside. The interior of the building was a single giant space, lit from above by the dull light that seeped through the cracked and jagged window panes in the ceiling and fell through a latticework of beams and girders to the bare concrete floor thirty metres below. Rows of huge columns stretching from floor to ceiling receded into the distance until they were lost in the gloom at the far end of the building. To Ace the vast empty space had the feel of a deserted cathedral, some huge place of worship once consecrated to the gods of heavy industry, now stripped of its icons and abandoned by its followers, left to moulder in dust and silence. She followed Peter into the centre of the factory floor, noting as they walked the dull blots of ancient oil stains on the floor and the large patches of lighter-coloured concrete that marked the places where the machines that had been the heart of this building had once stood.

Ahead of her, Peter had made his way to the base of one of the tall columns near the middle of the factory floor. A small mound covered by a ragged grey tarpaulin speckled with dust and shards of broken glass lay at the foot of the column, almost invisible amongst the enormity of its surroundings. Peter knelt by it and carefully lifted the edge of the tarpaulin, dislodging small showers of fine dust from it as he did so.

"Here we are," he said, turning his head to address Ace as she approached. He grasped the edge of the covering with both hands and threw it lightly back, revealing the small pile of neatly stacked sticks of dynamite that lay underneath. Ace knelt beside him and picked up one of the light orange cylinders examining it closely before holding it up to her nose and sniffing it.

"Trinitrotoluene," she said happily. With her other hand she picked up one of a jumble of smaller metal cylinders piled next to the explosives. "And lead azide detonators," she added, holding both tubes before her and smiling with satisfaction. "Jackpot." She put the explosive and the detonator back with the others and began counting them, performing a quick calculation of exactly how much of it she would need to clear the rubble from the front of the TARDIS.

"Tri-what?" said Peter, making a puzzled face at her.

"Trinitrotoluene," replied Ace without looking up from her counting. "Otherwise known as TNT." Thirty two sticks and eight detonators, she thought. Say eight sticks to clear the door, another couple just to be on the safe side. . .

"Is that enough?" asked Alina, peering over the shoulders of the kneeling pair.

"More than enough," said Ace. Peter unslung his satchel from his shoulder and opened it and Ace began very slowly placing the orange cylinders inside. She paused for a second after the tenth and then thought what the hell and carried on until the satchel bulged uncomfortably with all thirty two sticks. She slipped the detonators into a side pocket on the satchel and carefully fastened it shut. Before Peter could take the bag Ace threw the strap over her shoulder and stood up, hefting the weight of the bag against her hip. Peter led them back across the echoing space of the factory floor to the doorway. He hovered around the edge of the opening, suspiciously eying the brooding presence of the building on the other side of the concrete strip.

"Wait here," he whispered to Ace. He pointed across at the other building. "The Baba Yaga's nest is in there. I'll make sure she isn't around before we go back to find your friend." He nodded at the satchel over Ace's shoulder. "We don't want to run into her in the tunnels carrying that."

Actually, thought Ace, this is exactly what I'd like to be carrying if we run into that thing again. And maybe a bazooka. But before she could say anything Peter had darted out of the door and begun jogging towards the other building. Ace hesitated a second before shucking the satchel off her shoulder and gently placing it on the floor.

"Look after that," she said to Alina, pointing at the bag. "Be very careful with it. I'll be back in a minute." And then she stepped through the door and sprinted after Peter.

She caught up with him just as they passed the small brick structure that they had emerged from, about halfway between the two larger buildings. When Peter noticed her coming up alongside him he turned and quickly looked her over (checking that I'm not stupid enough to have brought the explosives with me thought Ace) but otherwise said nothing and together the two of them ran on, slowing slightly as they entered the vast pale shadow cast by the building ahead. This building was a smilar size to the one they had just left but there were a row of shattered windows set into it at head height instead of a doorway and Peter led them up to crouch against the wall just beneath them.

They stood there for a moment with their backs to the wall catching their breath before Peter turned, slowly drew himself up to his full height and peered through the opening. After a moment's hesitation Ace rose up alongside him and poked her head above the windowsill. The window in front of her had been smashed, leaving only a fringe of dagger-like shards clinging to the edge of the frame. Like looking through a shark's mouth she thought, and then stopped, remembering the creature in the tunnels. Don't think about rows of teeth she thought grimly. Don't think about things with rows of jagged teeth. The interior appeared to be similar to the one that they had just left, a massive open space buttressed by rows of thick columns arrayed like the ranks of some terracotta army standing silently in the shadows. As she looked she began to notice faint lines within criss-crossing the space, only a few at first but then, as her eyes adjusted to the relative darkness, she saw that the entire building was strung with an intricate tracery of what looked like wires or cables. As more and more of the lines became visible out of the darkness the giant space began to resemble an enormous spider's web. All of the lines within seemed to radiate outwards from a central spoke near the heart of the building, high up in the air about halfway up one of the supporting columns. As she looked more closely at the point where the lines converged something caught her eye. Right at the centre of the web a single tiny red light slowly glowed on and then off again in the blackness, pulsing like some ghostly heartbeat.

At her side she sensed Peter stiffening, suddenly frozen into place. He slowly extended a hand to touch her shoulder and nodded his head towards the centre of the factory floor, almost directly beneath the centre of the web.

"There," he whispered. "At the foot of the column. Can you see her?"

"Where?" whispered back Ace. All she could see beneath the centre of the web were shadows. There appeared to be a cluster of small objects attached to the pillar at about head height but in the darkness Ace couldn't quite make out what they were.

And then something moved.

Not much; barely a flicker of motion, as if one of the shadows had twitched slightly, but something definitely moved there. As she looked closer she saw it again, like a wisp of smoke snaking between columns of shadow, moving slowly away from them, towards the far end of the building.

"Looks like she's leaving," hissed Peter. "She's heading for the stairs to the basement. We'll wait for half an hour before we go down; she should be out of the tunnels by then."

"And if we ran into her in the tunnels carrying the explosives, what would happen then? What would she do?"

"Carrying explosives?" said Peter. He gave a grim smile and nodded his head back towards the central column. "Then," he said, "We'd all end up as one of those."

Frowning, Ace looked back at the pillar, straining her eyes to focus on the small shapes attached to it, but she still couldn't make them out. A cluster of small, round shapes clinging to the cylindrical concrete column like barnacles, glistening faintly in the scraps of light that sneaked through the surrounding web. Something about them was familiar. Small, round, glistening white shapes-

And then she took a step back from the window, eyes wide, her hand raised to her mouth.

She knew what they were.

CHAPTER NINE

"What we're looking for is a large steel framed building, at least twenty metres high, preferably nearer thirty; ideally a large open space with easy access to exposed steelwork," said the Doctor, poring over the map before him, smoothed out as flat as they could manage on one of the larger slabs of debris. Albers hovered at his elbow, waiting. The rest of the patrol were lying amongst the rubble around them in a rough circle, warily eyeing the ruins that lay in all directions.

"Something big that you haven't managed to blow up yet," continued the Doctor, tracing lines on the map with his finger thoughtfully. "Most likely a factory or warehouse of some kind. Something nearby. . ." He looked up from the map at Albers standing by his side. "Where exactly were we when we met, Leutnant?"

Albers frowned and cocked his head to one side as he regarded the map. "About. . . here I should say sir," he said, placing his finger on the spot.

"And the thefts of your phone lines. . . where were they?"

Albers leant in closer to the map and thought some more. "Here," he said eventually, pointing again at a spot near their meeting point, "And here, here and here," he continued, indicating further locations.

"Hmm," said the Doctor, tracing a line between the points with a finger. "Then the nearest buildings large enough would be about. . ." he said, his finger wandering idly north of the other points, ". . .about, ah. . ." He looked up from the map and searched the line of ruins on the distant horizon, shading his eyes with one hand.

"About there," he said with satisfaction, pointing towards two large pale silhouettes just visible against the skyline. He reached down to pick up the map, folded it and passed it back to Albers. "That's where they'll try to build a new transmitter."

"But that's on the other side of the frontline sir," protested Albers as the Doctor began walking towards the distant shapes. "There's no way we can make it through. It's impossible."

"Impossible," snapped the Doctor, stopping mid-stride and rounding on him, "is not in my lexicon. There's always a way."

The young officer looked doubtfully at the stretch of wasteland between them and the far-off buildings and shook his head. "There's just no way across it sir," he replied apologetically. "Ivan's dug in pretty deep around there. They've got snipers, machine gun nests, anti tank guns. . ." He waved his hand in a broad arc across the horizon. "They've fortified the line across this whole stretch of the front, from here all the way down to the river bank in the south," he said. "We can't outflank it."

"So we can't go across it," said the Doctor, following Albers' gaze across the broken landscape in front of them, "and we can't go around it either. Lucky for us then, Leutnant," he continued, turning his gaze to look down at the ground at his feet, "that the universe we live in has more than just the two dimensions."

o o o

The hunter stalked silently through the forest of pillars towards the far wall, where a stairway led down to the basement levels. All around it hung the fruits of its labours, the web of cables that threaded through the interior, connecting the damaged pulse modulator to a dozen or so carefully chosen points on the metal skeleton of the building. As it walked it threw a single look back over its shoulder towards the modulator, attached to the side of one of the central columns, high up in the air. The status light still winked reassuringly on and off in the darkness but the hunter was all too aware of its limitations as a technician. The human projectile that had struck its landing capsule had virtually obliterated the craft; it had been lucky to find any trace of the communication system in the debris field, luckier still to have found the pulse modulator, the most important part, but it had been badly damaged in the explosion and the hunter's rudimentary knowledge of its workings was just barely sufficient to restore it to minimal function. With the unit damaged and the rest of the transmitter destroyed it had been necessary to amplify the weak signal by using one of the human structures as a primitive aerial. Luckily many of the humans that it found in the area around the site carried convenient lengths of wire which could be adapted to this purpose and the work had progressed quickly. Its first attempt at transmitting had ended when the humans had directed a heavy concentration of their indirect-fire weapons against the building it had chosen, and it had barely made it out of the collapsing shell of the structure with the irreplaceable pulse modulator in time, abandoning the almost-completed network of cables seconds before a barrage of high explosive fists had hammered the site into rubble.

Now it was nearly ready once more. The modulator had been programmed with the message, ready to transmit once the last wire was in place and the final connection was made.

It gave a low growl of satisfaction. One more cable. Just one more and it would be complete, and the message would be sent.

It paused at the top of the steps and took one last look at the web of transmitter cables that radiated out from the silently blinking modulator like the rays of a setting sun and then loped easily down the stairs towards the basement.

o o o

"Over here sir!" called Albers, waving his arm above his head to attract the Doctor's attention. "We've found a way down!" He and two other members of the patrol were kneeling beside a low square of brick wall three metres to a side, one of the few pieces of intact brickwork sticking out of the rubble field. As the Doctor hurried over to them he saw that the waist-high wall enclosed a flight of stairs descending steeply into blackness. As the Doctor leaned over the wall and peered into the opening another of Albers' men appeared out of the darkness at the bottom of the stairs and trotted back up to the top.

"Leads into a basement sir," said the man, nodding back down the stairs, "but there's a hole in the wall that opens into the main sewer system."

"Well done Corporal," said the Doctor. He straightened up and looked towards the distant shape of their destination, narrowing his eyes in thought.

"If we bear north-north west for about a mile or so that should bring us close enough," he murmured to himself. He put one hand on the wall and vaulted over it to stand beside the corporal at the top of the stairs.

"Come on then Albers, no time to lose," he called over his shoulder as he pushed past the corporal and started down the steps. "Bring the rest of the men."

"Sir," began Albers, halting the Doctor's descent.

"Yes, what is it?" snapped the Doctor impatiently.

The young officer looked uncomfortable. "There have been reports that men have been going missing in the tunnels. Patrols go down and. . . and they don't come back up again."

"And what happened to them?"

Albers shrugged. "I don't know sir. No one does."

"Well then Leutnant," said the Doctor, turning away from him and continuing down the stairs until he was lost to sight and only the echoing sound of his voice came drifting back out of the opening, "Now's your chance to find out."

o o o

It strode through the echoing spaces of the deserted basement levels, through narrow corridors and low chambers and cavernous storerooms, all of them dark and cold and empty. In the spaces where the machinery and equipment had been removed when the building was evacuated ragged twists of wire and severed stubs of pipe emerged from the walls and floors like the sprouting shoots of some new breed of industrial flora. Small tinkling splashes of water and the furtive scurrying of rats were the only sounds to disturb the graveyard silence.

It made its way to the lowest level, to the room where the gaping mouths of industrial-scale waste pipes led into the red-brick arteries of the city's main sewage channels. It paused on the threshold of the tunnels and trained its audio monitoring systems on the opening, listening for any hint of movement. Satisfied that the immediate area was clear it climbed into the mouth of the outlet and dropped heavily through it into the ankle-deep water in the tunnel beneath. It initiated a limited diagnostic of its weapons and sensors and watched the slow scrolling of the status indicators on its head-up-display, primed its plasma cannon and placed its targeting suite on standby. Only one more length of wire was required to complete the transmitter; it would not allow anything to get in its way now.

It turned and stomped into the darkness, fountains of black water blossoming with each heavy footfall.

CHAPTER TEN

The hole in the basement wall led the patrol into a narrow, low-ceilinged passage that ran in total blackness for more than twenty metres before merging into a much larger tunnel that was obviously one of the main branches of the city's sewer system. It stood nearly three metres tall and more than six across, a flattened tube of roughly-textured concrete that disappeared out of sight in both directions. A slow-moving sheet of grey water two or three centimetres deep covered the floor of the tunnel, gurgling quietly out of the darkness ahead of them, coursing around their feet and then disappearing into the darkness in their wake. Occasional shafts of light speared out of shafts and holes and cracks in the walls and ceiling and by this dim light the patrol crept northwards along the watercourse. The mouths of smaller passages that opened into the main tunnel dotted the walls like gaping mouths every fifteen or twenty metres and the men covered these openings warily with their weapons as they passed them, alert to any hint of noise or motion.

The man who had discovered the entrance to the tunnels, Corporal Baumann, took the position as lead scout at the head of the formation, followed closely by the Doctor and Leutnant Albers. The rest of the men came after them in two files, one on either side of the tunnel. From time to time the distant booming of explosions on the surface shook the ceiling like a series of miniature earthquakes and as their advance brought them closer to the frontline of the fighting on the streets above these became more frequent until they seemed to merge into one continuous rumbling of thunder.

Baumann, in the lead, moved forward cautiously, slightly crouched and sweeping the barrel of his rifle in long, slow arcs to cover the darkness ahead. The Doctor, a few paces behind him, walked somewhat more casually although, Albers was relieved to notice, this time he seemed to be resisting the impulse to whistle or break into song. Every few minutes the Doctor paused and waved the rest of the patrol to a stop and they waited as he stood with his head cocked to one side as if gauging something until, evidently satisfied, he waved them on again.

Eventually, after perhaps half an hour of this creeping advance the detonations above them lessened and became more sporadic again and Albers judged that they must have passed the worst of the fighting above, a thought which gave him a second or two of comfort before he realised that they were now on the Soviet side of the lines and a long way away from any help should they run into trouble. He found himself nervously tightening his grip on his submachinegun and when he tried to swallow he became aware how uncomfortably dry his mouth was, all the more so because of the constant slow trickling of water around his boots.

At the front of the group, Baumann suddenly stopped, bringing the rest to a halt. He took one hand off the stock of his rifle and slowly raised it level with his head, palm open in the signal for patrol halt. The rest of the men sank into crouching positions and waited as Baumann gripped his rifle with both hands again and took two careful steps forward and then stopped again, aiming his rifle into the black depths ahead. As quietly as he could, the Doctor walked forward until he stood just behind and to the left of Baumann. He stared past him into the gloom before them but could see nothing in front of them but more tunnel.

"What is it Corporal?" he whispered. "What can you see?"

Baumann slowly shook his head, still searching the shadows. "I don't know sir," he whispered back. "I thought I heard something."

o o o

A threat warning lit up on the hunter's head-up display, flashing furiously on and off to demand its attention. Chemical sensors in its helmet that continuously searched the air around it had detected prey-scent drifting on the air from somewhere ahead and it quickly punched in the sequence of commands on the control panel on the forearm of its armour that brought up the details on its helmet display. What it saw made it almost purr with pleasure. Not only were there high concentrations of stress pheremones and a strong waft of carbon dioxide that indicated the breathing of multiple contacts but also the telltale chemical traces of primitive armaments; a hint of gun oil and a far more powerful scent of the weak explosive that the humans used in their projectile weapons. It powered up its auditory sensors and trained them on the tunnel ahead. After a few seconds it picked up the distant echoes of feet slapping on wet concrete, slow and hesitant but regular, and drawing closer. From these sounds and from the strength of the chemical traces it estimated that there was a group of no less than eight and perhaps as many as twelve humans approaching, bearing weapons.

Eight to twelve targets. It placed its weapons systems on maximum readiness and quickened its pace, moving to intercept.

o o o

"Probably nothing," said Baumann, but he didn't look convinced by his own denial and the wandering muzzle of his rifle continued to search the darkness.

Albers came forward to join Baumann and the Doctor. At his approach the Doctor turned towards him and motioned him to come close.

"This is about as far north as we needed to come," said the Doctor. "Now we need to bear west." He pointed towards the mouths of some of the smaller tunnels set into the wall on their left. "One of these should do, if we can find one that runs straight for a hundred yards or so. By my estimation that should take us almost directly underneath those factories. " He turned to the corporal and whispered "Baumann," but the man seemed not to hear, still squinting suspiciously into the darkness.

"Baumann," he said again, slightly louder, and was about to put a hand on his shoulder when he noticed the man tensing, tightening his grip on his rifle and bringing the stock firmly into his shoulder, taking aim at a definite point now rather than slowly sweeping the space in front of them. Lowering his hand, the Doctor followed the direction of Baumann's gaze. In the scant traces of light the water that flowed towards them was a dull grey sheet that covered the floor, interrupted only by their boots which it broke around in thin plumes of bubbling froth, making their feet look like islands in a stream. Baumann was staring intently at a spot on the tunnel floor some fifteen metres ahead, right on the edge of their vision, where the flow of water appeared to be similarly disturbed, as if it were coursing around something standing right in the middle of the tunnel, but the space above the disturbance was empty. Albers, standing beside the Doctor, seemed to be about to speak but the Doctor motioned him to silence with a quick movement of his hand.

The barrel of Baumann's rifle tracked slowly upward from the point where the water diverged until it was aimed at a point about chest-high, directly above it. The ghost of a smile crossed his face.

"There," he breathed quietly.

And then there was a blur of motion in the darkness in front of them and a strange humming buzzsaw-sound as something metallic and blindingly fast ripped through the air and sheared straight through Baumann's neck. Its speed was such that it took a few frozen moments for his head to register its sudden lack of attachments and topple backwards off his shoulders, landing in the flowing water behind him with a dull thump. Small spurts of arterial blood fountained from the top of his neck as his headless body, still tightly clutching his rifle, slumped to the ground with a loud splash.

Albers, eyes wide with shock, had just opened his mouth to speak when the Doctor hurled himself into the man as hard as he could, knocking him off his feet just as the object that had decapitated Baumann arced back out of the tunnel behind them on its return journey, through the spot where Albers had been standing and back to its point of origin.

There were shouts of fear and alarm from the rest of the patrol crouched along the sides of the tunnel behind them, and then the shooting began.

o o o

It retrieved the kill-disc with a distinct lack of satisfaction. It had despatched its primary target, the lead scout who had been on the point of locating it, but it had been denied the aesthetic elegance of a second kill from a single cast of the disc by the intervention of one of the prey-animals, anticipating the disc's return and pushing the other out of its path.

It growled its frustration at this disappointment. It lived for the artistry of the clean kill, the gracefulness of despatching prey with maximum precision and economy of effort. Now, alerted to its presence, the prey that trailed behind the lead group began to fire their weapons. The first few shots flew harmlessly wide but in the confined space of the tunnel even random, unaimed shots might eventually find a mark.

More shots flew past; one glanced off its chest armour. Another whistled mere centimetres past its helmet.

Its growl turned into a low snarl. It extended its wrist blades, twin serrated knives almost half a metre long snicking into place from their housings in both gauntlets.

The time for artistry was over.

CHAPTER ELEVEN

They returned to Peter and Alina's bunker by the way they had come, moving even more slowly than they had on the way up now that Ace was carrying enough explosives to demolish a tower block. The two boys, Stepan and Mykola, were where they had left them, still sitting either side of Alina's mother, huddled close by the stove.

Peter insisted that they needed to wait for at least half an hour to ensure that the Baba Yaga had cleared the tunnels before they set out for the TARDIS and Ace spent the time trying to cheer up Alina and the two timid boys by teaching them some songs. She had exhausted her stock of traditional children's songs within about five minutes and had moved on to something a bit more contemporary (for her, anyway) when she heard the first faint sounds of gunfire from outside. Breaking off halfway through a spirited, if somewhat flat rendition of Yesterday, she moved quickly to the covering that led into the tunnels, drew it back and stuck her head through the gap. Without the muffling of the sheets covering the entrance the sounds of shooting were much clearer, rolling and echoing down the length of the tunnel towards her. The firing was heavy enough that the individual shots seemed to form a single continuous noise like the distant roaring of some huge engine.

Peter joined her at the opening, poking his head through the covering beside her. Ace looked at him and nodded her head in the direction of the shooting.

"Sounds like quite a fight."

"It'll be over soon," replied Peter. "Once she's dealt with them it should be safe for us to go and find your friend."

"But what if she loses?" said Ace, listening to the continuing hollow booms. They had started to lessen in frequency now and she could make out the sounds of individual shots within the cacophony. "What if the soldiers kill her?"

Peter shook his head decisively. "No chance," he said. "Whoever that is," he continued, looking down the tunnel, "They're dead already."

o o o

When the Doctor knocked him over Albers came down heavily on the wet concrete floor, dropping his submachinegun and sending it clattering out of reach. He was in the process of levering himself up onto hands and knees and reaching out for it when the first shots rang out behind him. The detonations were deafingly loud in that confined space. The crack of each shot was magnified into a booming roar that rolled down the tunnel like a wave, echoing and reechoing out of each of the smaller tunnels that branched off of it, turning every one into a thunderous symphony. The first volley of rifle shots were bad enough, but when the patrol's machinegunner opened fire the sound struck him like something physical, a succession of huge explosions that gathered power as they reverberated from the walls and floor and ceiling and seemed to batter him from all angles, overwhelming his senses until it felt like the only things left in the world were noise and pain. Instinctively he put his hands to his ears and lowered his head, hunching into a foetal position, eyes shut tight. The part of his brain that remembered his training was screaming at him to get up, to lead his men, but the screaming was crowded out by the brutal hammering noise all around him.

Suddenly, mercifully, the constant roar of the machinegun fell silent, although Albers took a few seconds to register this. His head was still ringing inside his helmet and he remained crouched on the floor for a few moments more before his senses returned. Single rifle shots still rang out at random intervals but in his dazed state they seemed to be coming from a long way away.

How long have you been kneeling here, you idiot? yelled a voice from the back of his head. Enemy contact! Getupgetupgetup-

He took his hands from his ears and sat up and opened his eyes in time to see the last two members of his patrol die.

o o o

It crouched, coiling power in its legs like springs and then leapt over the body of the dead prey-beast and the two others that lay beside it, landing with a solid thump in the middle of the tunnel, directly between the leading members of the two lines of men crouched against either wall. It bounded left, in the same motion flicking out one arm to spear the man that stood there through the chest, killing him instantly. It noted with irritation a volley of automatic fire hurtling past it, the white-hot bullets forming a solid line that lanced through the air like a swarm of speeded-up fireflies. It identified the source, a prey-beast near the rear of the column firing one of the repeating weapons the humans favoured.

That one next.

It span around and leapt again, reaching for its kill-disc and hurling it towards the machinegunner in one fluid motion as it did so. The disc struck the man just as it landed, bisecting him cleanly at the waist at the same time that the hunter decapitated the man it landed beside with a lazy swing of its forearm blades. It was gratified to note the kill-disc shearing through another target on its return path, severing an arm and carving a deep trench through the human's torso just above the waist.

The remaining humans were still shouting and continuing to fire blindly down the tunnel, unable to see it through its camouflage. It caught the kill-disc on its return just as a rifle shot, by chance or design pinged off the side of its helmet. Angered, it hurled the kill-disc at the human responsible so hard that it cleaved his head and upper torso in two and left the disc embedded firmly in the wall behind. It despatched another human with a casual backhand flick of its blades, neatly disembowelling it and then turned to face the remainder. There were only four remaining now, the unarmed one lying on the floor, the one hunched into a ball and two more that continued to fire in its general direction, still unable to pinpoint it and unable to comprehend the sight of the invisible death that had scythed through their comrades.

It trained its shoulder-mounted plasma cannon on the last two armed targets, not bothering to activate the targeting scanner at that close range, and fired two shots in quick succession. The first struck cleanly, punching a hole the width of a fist through the prey-beast's chest and dropping it instantly. The second was slightly off-target and while it took half of the human's head off in passing the shot still retained enough energy to blow open a hole in the wall behind it a metre wide, sending out a massive eruption of dust and tumbling fragments of concrete, followed immediately by a gushing stream of freezing black water that spouted and pulsed out of the opening and quickly spread across the floor of the tunnel in great slopping waves. It watched the sudden tide flow past its feet for a moment and watched without interest as it leeched heat from the bodies of the fallen humans, saw their heat-shapes darken as the water coursed around them and their last traces of warmth ebbed away.

Then it looked up, and turned towards the last of them.

o o o

The Doctor stood absolutely still. The echoes from the blast of the energy weapon that had killed the last two of Albers' men and blown a hole into an adjoining waste pipe in the process were still roaring and booming through the tunnel system and they merged with the still-ringing sound of the last few gunshots into a fading concerto of destruction that rushed away from them into the darkness. Albers lay beneath the breach in the wall, directly underneath the flow of water still surging out of it. He seemed to have been concussed by the blast and was floundering feebly against the pouring waters.

The Doctor stared hard at the spot where the two energy blasts had originated and soon made out the rippling outline of a man-shaped figure standing there, a faintly shimmering shape that was only visible if you knew exactly where to look. Well well, thought the Doctor. Directed energy weaponry, remotely targeted kinetic projectiles and active camouflage. What else do you have in your box of tricks?

He stood up straight, facing the apparition head on and slowly put his hands on his hips.

"Come on then!" he shouted defiantly. "Show yourself!"

o o o

The hunter paused, confused. Where it had expected to find two cowering prey-beasts there was only one, and it was definitely not cowering. It seemed, unbelievably, to be making some sort of show of defiance, tiny and unarmed and helpless as it was. It was squaring up to the hunter head on in a posture that could only be described as confrontational.

And then the prey-beast shouted at it.

Interesting.

It retracted its forearm blades and then keyed in the sequence of commands on its forearm control panel that disengaged its cloaking system.

o o o

The blurred area of space rippled like the surface of a pond and then receded, revealing a giant grey-green armour-clad figure standing there. Thick braided cable-like strands hung from the sides of its helmet like dreadlocks. On its left shoulder a gun-like device on a gymballed mounting twitched restlessly, the barrel swivelling to and fro as if searching for something.

It took a single step forward, the visored-face of the helmet staring balefully at the Doctor, towering over him. The black waters were still surging out of the hole in the wall and rushing around their feet, slower after the initial violent outburst but still sufficient to cover the shivering figure of Albers who lay almost wholly-submerged under the rushing current, only his head and weakly-twitching arms above the waters. The combination of the deafening noise of the gunfire and then being caught in the blast of the plasma discharge that had blown the hole in the side of the tunnel seemed to have stunned him and he lay unresisting under the freezing flow.

For long seconds the creature continued to regard the Doctor standing brazenly before it and then its helmet turned right and then left, searching the area around them. Its gaze swept over the quietly-spluttering figure of Albers without pausing.

It can't see him, thought the Doctor as it continued to look around the tunnel. Interesting.

"Whatever you are," said the Doctor firmly, drawing himself up and gripping the lapels of his jacket with both hands, "This is not your world." The creature stopped its searching and turned its gaze back onto the Doctor.

"Leave this planet," continued the Doctor quietly. "Or I'll not be answerable for the consequences."

It continued to regard the Doctor levelly and then tilted its head to one side as if in thought. The questing barrel of the energy weapon on its shoulder ceased its movements and then turned with a tiny whir of motors to point very slowly and very deliberately straight at the Doctor's head.

o o o

Still puzzled at the sudden disappearance of the last armed prey-beast, the hunter considered the small yet oddly unafraid figure that confronted it. It trained its plasma weapon on the creature and then activated its sensors and ran a detailed scan which, while it revealed several curious anatomical differences from the other prey, only confirmed its initial assessment that it was wholly unarmed.

It looked around once more in search of the missing target but all it saw were the bodies of its victims lying sprawled on the floor all around it, their heat-shapes slowly fading to black as they cooled in the freezing water. Disappointed, it slowly turned away and resumed its march down the tunnel, pausing only to tug the embedded kill-disc from the wall and slip it back into place in its holder. It reengaged its cloaking systems and strode invisibly into the darkness.

o o o

Struggling under the rushing waters, almost paralysed from cold and shock, Albers fought to speak.

"F- f- f-", he stammered. The Doctor ignored him, still gazing thoughtfully towards the spot where the giant creature had disappeared.

"F- f- f- f-" began Albers again. The shivering in his limbs was almost uncontrollable now.

"F- f- f- freezing," spat out Albers eventually. The Doctor turned to look down at Albers lying shaking under the frothing torrent still pouring out of the gap in the wall.

"Yes Leutnant," he said eventually, favouring him with a small smile. "I'd imagine that's what's just saved your life."

CHAPTER TWELVE

Peter led the way, followed by Ace carrying the satchel with the explosives and then Alina bringing up the rear. They had left the basement that Peter and Alina called home shortly after the final echoes of the distant firefight had faded away and set out to return to the place where Ace had met Alina.

Once we get there I should be able to trace the route back to the TARDIS, thought Ace as they shuffled cautiously along one of the narrow tunnels that branched off of the main waste channel. If I can just get the Doctor into the TARDIS medical bay and get him back on his feet he'll know what to do about the so-called Baba Yaga. She harboured serious doubts about the folkstory origins that Peter claimed for the creature, especially after seeing what she strongly suspected to be signs of alien technology in its lair.

She stopped as, in front of her, Peter paused at the intersection of two tunnels, peering down them before resuming his march and waving them onwards.

But if the Doctor destroys it or drives it off, what then? she thought, feeling a sudden sense of guilt as she watched Peter silently leading them into the darkness. She hefted the weight of the satchel on her shoulder and glanced quickly at Alina trailing behind her as she did so. These people rely on that creature to keep the soldiers away. Whatever else it is, it's the only thing keeping them alive right now. Do we have the right to take that away from them? She remembered Alina's mother and the two boys waiting back in the basement room, hiding from the war behind their totems of bent and broken rifles and wondered how long it would take for the war to find them again if the creature no longer stalked the ruins above.

She made herself remember the creature's lair adorned with its own grisly totems, the arrangement of bleached-white human skulls sprouting from the building's central pillar like bunched fruit. It's not protecting everyone, she reminded herself.

She was still struggling with this dilemma when she noticed that Peter had halted again some five paces ahead of her. She stopped and put out one hand behind her to gesture to Alina to do likewise.

Peter stood listening at the mouth of another tunnel that branched off from their own. After a few seconds he turned his head to face back down the tunnel towards the others. His face was very pale.

"There's someone else down here," he whispered, pointing towards the opening of the intersecting tunnel. For the first time since Ace had met him there was real fear in his voice.

"I think they're soldiers."

o o o

After the Doctor had helped Albers out from underneath the flowing water and into a sitting position up against the tunnel wall he strolled slowly along the tunnel through the site of the battle, stepping around the fallen bodies as he went. Occasionally he stopped to kneel over one of the sprawling figures to inspect them more closely, gingerly probing at wound channels and the ragged edges of severed limbs before rising to his feet and continuing. The only sounds in the tunnel were the gurgling of the escaping water and the slow slooshing sounds the Doctor's feet made as he waded through the ankle-deep current. He stopped at the point where the last two bodies lay and then turned about and slowly paced his way back, hands in pockets and seemingly deep in thought, towards the spot where Albers still sat shivering uncontrollably. The young officer looked up as he approached. In the space of the last five minutes his face had become haggard and drawn. New lines had appeared, surrounding his facial features like rows of freshly-dug trenches.

The Doctor stood silently regarding the shaking figure of the young man for a few moments before he spoke.

"I would imagine," he said at length, "that you have some questions."

Albers looked blankly up at him for a long time before answering.

"My men-" he began eventually, his voice wavering.

"Dead," said the Doctor sharply, cutting him off. The word struck Albers like a slap and he slumped back against the wall, his eyes closed. His head sagged forward heavily against his chest. The Doctor moved to his side and knelt next to him.

"There wasn't anything you could have done, Leutnant," he said, more gently this time. "Once that thing decided to attack nothing on Earth could have stopped it."

"But I should-" began Albers, then stopped. His voice sounded small, almost childlike. "I should have. . . I mean. . . I. . ." His voice tailed off. He opened his eyes and looked at the Doctor kneeling beside him. His face seemed to be begging forgiveness. "It all happened so quickly sir. I mean. . . I didn't have time to. . . to. . . and the noise. . ."He broke off again and put his head in his hands. His shoulders trembled and shook as he was racked by a series of convulsive sobs.

The Doctor put a hand on his shoulder and gave a reassuring squeeze. "There was nothing you could have done," he said again. He looked up and gazed back down the tunnel and watched the black water gushing from the hole in the wall and frothing and tumbling around the remains of men.

"There was nothing anyone could have done," he said sadly.

o o o

Peter backed very slowly away from the mouth of the tunnel, placing his feet with exaggerated care as if afraid of waking some slumbering beast within. As he did so Ace heard the faint sounds coming from the opening, sounds that became clearer as she listened and then became voices.

Including one very familiar one.

Pushing past Peter's attempts to hold her back she ran into the tunnel towards the sound of the voices. The tunnel was narrow and low-ceilinged and she stooped as she entered, hefting the weight of the heavily-laden satchel against her hip. The slapping of her boots on the wet concrete floor made a hollow ringing sound that echoed around her as she ran.

"Professor?" she called out as she ran. Then again, louder. "Professor!"

She reached the end of the passage and emerged into a much wider and higher tunnel running out of sight in both directions. Almost directly in front of her on the opposite side of the tunnel sat the slumped figure of a man in a soaking wet grey uniform, helmeted head cradled in his hands, and beside him knelt the Doctor.

"Professor!" called out Ace happily. A surge of relief ran through her at the sight of him and she splashed across the tunnel floor, reaching him just as the Doctor rose from his crouch by the other man's side and crashing into him in a hug that was, she reflected after the event, somewhat more robust than was wise for someone carrying a bag full of volatile explosives.

"I tried to wake you but you were unconscious and I couldn't get into the TARDIS so I had to go for help," said Ace, the words pouring out of her in a rush. "I had to leave you to go and find-" She broke off as she noticed for the first time the litter of bodies scattered across the tunnel floor behind the Doctor. Water poured through a breach in the wall a few metres from where the Doctor's silent companion sat and flowed around the sprawled figures, making them look like unwanted statues abandoned in a river delta. It took her a few seconds to connect the scene with the sounds of shooting they had heard earlier.

Following the direction of Ace's gaze the Doctor looked once more over the morbid tableau behind him.

"Ace," he said, his face serious. "There's something I have to tell you. There's-"

"There's an invisible alien in the city and it's killing anyone carrying weapons," said Ace quickly, cutting him off. "It has a base," she continued, enjoying the growing look of astonishment on the Doctor's face, "about two hundred metres that way." She pointed back towards the tunnel mouth from which she had emerged just as Peter's face nosed cautiously out of the opening.

"You're getting good at this," said the Doctor admiringly as Ace beckoned to Peter to join them. Peter stepped into the larger tunnel followed by the smaller figure of Alina and the pair hesitantly crossed over to them. They seemed nervous and it took Ace a moment to realise that their wariness was directed at the trembling young man propped up against the wall beside the Doctor rather than the bodies strewn about them.

"Professor," said Ace as they approached. "This is Peter and Alina. They've been helping me." The pair nodded and mumbled polite Hellos to the Doctor but they couldn't take their eyes off of the grey-uniformed man at his feet.

"Ah yes," said the Doctor. "Introductions. Ace, Peter, Alina; this," he said, indicating the soldier, "is Leutnant Albers. Albers; this is Ace, the companion that I mentioned earlier."

"Pleased to meet you," said Ace. "Any friend of the Professor's. . ."

"You're a Professor?" said Albers from his seated position against the wall, looking from the Doctor to Ace and then back again. He was obviously struggling with the turn of events and sounded confused. "But I thought that you were. . . you said you were in military intelligence."

"I said nothing of the sort," said the Doctor. "I merely observed that you hadn't been at the front long enough to recognise a member of German military intelligence. Frankly, the fact that you thought I was one just goes to prove my point."

"But. . . but. . ." spluttered Albers. "You said that your superior was. . . you implied it was. . ." He pointed one finger hesitantly upwards. "You know. . . " He looked around as if someone might overhear them and his voice dipped to a whisper. "The Fuhrer."

"Again, I said no such thing," said the Doctor evenly. "You mentioned some names and I pointed my finger upwards twice and then waggled my eyebrows. Any conclusions that you may have drawn from that are entirely your own responsibility." He left the officer to digest this and addressed Ace. "How did you know about the alien?"

"Saw it earlier," said Ace as casually as she could, enjoying the Doctor's admiration more than she would have admitted. "Went and checked out its base, had a look around. . . you know; the usual."

"What do you mean, alien?" broke in Peter, looking at the Doctor and Ace as if they were mad. "Are you talking about the Baba Yaga?"

"The Baba Yaga?" snorted the Doctor. "My dear boy, what we're dealing with is no fairy tale. Fairytale creatures, as a rule, tend not to use phased plasma blasters or adaptive-refraction camouflage devices. And besides," he said, "this is way too far west for the Baba Yaga. She lives in Irkutsk and she's actually very nice once you get to know her. Believe me, this is something far worse." He turned back to Ace. "You said something about it attacking people carrying weapons."

"Peter and Alina say that it leaves you alone if you're unarmed. I don't know if that's true." She shrugged. "It didn't attack us when we saw it earlier."

"Hmm. Well that explains a few things. And you mentioned a base?" said the Doctor. "Where? Have you seen it?"

"It's in an old factory on the surface, back that way," replied Ace, waving a hand back the way they had come. "I've had a look inside. It's got loads of wires strung up in it like a cat's cradle and there's some sort of device with a light on it, right in the middle."

"That'll be the pulse modulator," said the Doctor, nodding his head thoughtfully. "Its first attempt to send a signal was interrupted so now it's trying again. I suppose you have to admire its persistence."

Albers struggled to his feet with some difficulty to stand beside them, looking from one to the other with a look of baffled incomprehension that almost exactly mirrored the expressions on Peter and Alina's faces as they silently followed the conversation back and forth. He stood like that for a few moments, his lips twitching slightly as he tried to think how to frame his question.

"Who," he said eventually and then stopped. He tried again. "What was that. . . that. . . thing?"

"An extraterrestrial lifeform. An alien, Leutnant; a creature from another world," said the Doctor gravely. "I don't know its purpose was in coming to this planet but I suspect that now it's trying to send a message back to its homeworld, and killing anyone who gets in its way." He looked up and stared into the darkness at the point where it had disappeared.

"It's the enemy, Albers," he added quietly. "And we must stop it."

CHAPTER THIRTEEN

At the Doctor's insistence Peter and Alina led the group back through the tunnels to their home, although neither of them could keep from darting suspicious looks at the bedraggled figure of Albers trailing meekly behind them. The young officer seemed subdued and hadn't said a word since the Doctor's explanation earlier, trying to make sense of what was happening to him. When they reached the basement room he allowed himself to be ushered inside without comment and then picked a spot against the wall and sat down, still deep in thought. Stepan and Mykola looked at him curiously when he entered with the others but said nothing. Alina's mother, still sandwiched between the two boys didn't even look up and continued to stare lifelessly into space.

Once they were all inside the Doctor took Ace to one side while the others huddled by the stove.

"Alright Ace," he said. "How much Nitro-9 did you bring with you?"

"None," replied Ace.

"Well that should be-" He broke off mid-sentence with a look of confusion on his face. "Wait, what did you just say?"

"None," repeated Ace and then added, slightly embarrassed, "I left it in the TARDIS."

"You left it in the TARDIS?" said the Doctor incredulously. "We arrive in the middle of the battle of Stalingrad and that's the one time you forget to bring any Nitro-9?" He looked at her disbelievingly and shook his head. "That's like Jimi Hendrix turning up at Woodstock without his guitar."

"I've got this," said Ace, lifting the flap of the satchel to reveal the stack of charges. "It's only basic TNT but there's quite a lot of it."

"Enough to demolish that factory you mentioned?"

Ace thought about this and frowned. "Probably not," she admitted eventually. "But there are a couple of storerooms coming off of the corridor that leads to the factory that looked like they had some industrial chemicals in them. If we have some time," she added, nodding her head at the contents of the satchel, "I could try pepping these up a bit. You know - add a bit of extra boom."

"Well alright," said the Doctor, looking doubtful. "But don't do anything too drastic. We don't want to leave behind any technological innovations that would contaminate the timeline."

"Relax Professor," said Ace breezily. "It's not as if we'd be giving them the secret of the atomic bomb."

"Atomic bomb?" said Albers, looking up at them from his spot against the wall nearby. "What's that?"

"Tiny bombs, the size of atoms," snapped the Doctor, spinning to face the man and glaring him back into silence. "Very useful for blowing up ants." He turned back to Ace. His face was wearing what most people would have taken for a smile but which anyone who was as familiar with him as Ace was would recognise as anything but.

"Ace-" he began in a warning tone.

"Alright Professor," she said quickly, putting up her hands in a placatory gesture. "I promise I won't do anything to contaminate the timeline."

On the other side of the room Alina chose that moment to begin leading the two boys in a song.

"Yesterday," she sang quietly, "all my troubles seemed so far away. . .now it seems as if they're here to stay. . ."

The Doctor turned to look at the girl with a strangled expression on his face and then turned his head very slowly back to face Ace, the smile-that-was-not-a-smile replaced by a glare-that-was-very-definitely-a-glare. Ace gave a small gulp.

"Starting," she said, forcing an innocent expression onto her face and trying to sound as earnest as she could, "right now."

o o o

Convincing Peter and Alina that the creature that they called the Baba Yaga was actually a being from another world wasn't as difficult as Ace had thought it would be. Neither of them would have survived this long if they were stupid and it didn't take much persuasion for them to admit that on balance the weight of evidence pointed more towards alien creature with advanced technology than it did towards fairy tale witch-of-the-woods.

Convincing them that they ought to do something about it however proved to be rather more difficult.

"Why do we need to do anything about her? Why can't we just leave her alone?" said Peter indignantly when the Doctor had assembled the group around the stove, explained the purpose of the creature's lair and announced his intention to destroy it. "She only attacks people with guns! As long as you're unarmed she's no threat to anyone!"

"It's not a threat to you now," agreed the Doctor, refusing to adopt the female pronoun. "But who knows what message it's planning to send once its transmitter is complete? Suppose it's the first scout of an invasion fleet? Suppose there are thousands more like it, just waiting for the signal to land?"

"If thousands more of them land then that just means they'll kill everyone with guns," snapped back Peter. "Why should we stand in the way of that? We don't want to carry guns. We just want the soldiers to go away and leave us alone so that we can get on with our lives."

I didn't realise, thought Ace. I thought they were just afraid of the Germans but it's much more than that. They hate the soldiers of both sides for this, for destroying their lives, their homes, killing their friends and families. She took another look around the dank basement and the pathetic remains of their possessions. Who can blame them for hating men with guns when they've reduced them to this?

"It's not supposed to be here," insisted the Doctor. "This is not its world. It's out of place and it must be stopped before it can do any more harm."

Peter rose angrily from his seat by the stove and glared at the Doctor. "Try it then," he said with barely suppressed fury. "Go and try it, and see what happens to you. If you go into her nest carrying explosives, she'll kill you." He looked from the Doctor to Ace and then to Albers, still slumped against the wall on the far side of the room and playing no part in the conversation. "All of you." From his body language it was clear that he wanted to storm out on them but was unable to do so in the confined space of the basement and so he folded his arms across his chest and turned his back on them instead.

Alina looked apologetically at Ace. "I can't help you either," she said. She looked to the still figure of her mother and the uncomprehending faces of the two small boys beside her. "Someone has to look after this lot."

Ace smiled back at her reassuringly. "That's OK." She turned to the Doctor. "Looks like it's just you and me then Professor."

The Doctor opened his mouth to reply when a voice piped up behind them.

"I'll come with you," said Albers. Unnoticed by the others he had risen from his resting place on the floor and now stood behind the Doctor and Ace. "I'll help," he added. "If I can."

The Doctor looked him up and down sceptically. The young man's uniform was soaked through and filthy from the drenching in the tunnel but he had stopped shaking now and, while he still looked slightly subdued, seemed more like the man he had been before the battle in the tunnel.

"Are you sure you're up to it?"

Albers gave a small shrug and looked at the floor at his feet. "It killed my men," he said simply. "I have to help, for their sake."

The Doctor looked at him for a few moments more and then gave a small shrug of his own.

"Alright then," he said at last. "Let's go."

Ace adjusted the weight of the satchel, seating it more comfortably on her shoulder and then took a last look at the others gathered around the stove. With the hand that wasn't gripping the satchel's strap she gave Alina a wave.

"Bye Alina," she called out. "And thanks for everything." The girl gave a small wave and a smile in return. Ace looked towards Peter but he still had his back turned to her. She went to the doorway that led to the factories above, pulled back the canvas covering and ducked through it into the corridor beyond. The Doctor went to follow her.

"Wait," said Albers behind him. The Doctor turned to see him taking his pistol from its holster and holding it up with a questioning look on his face.

"Should I bring this?" asked Albers.

"That depends," replied the Doctor.

"Depends on what?"

"It depends on how well insured you are," said the Doctor. "If you have a policy that pays out a large cash sum in the event of you being disembowelled by an invisible extraterrestrial killing machine then by all means, bring the gun with you." He fixed Albers with a cold stare. "If not then I'd strongly advise you to leave it here." He turned away and followed Ace through the opening.

Albers looked uncertainly at the gun in his hand and then, after a moment's hesitation, put it down on one of the mattresses lining the edge of the room and, without a word to the others, followed the Doctor out of the room, letting the flap fall closed behind him.

CHAPTER FOURTEEN

The corridor Ace led them into was narrow and unlit and they felt their way along the walls to a short flight of stairs at the end of it. The stairs ended in another corridor, longer than the first, with more stairs leading upwards at the end of it and a row of open doorways set into it along one side. There was a powerful smell of industrial chemicals in the air.

Ace carefully put her satchel down against the wall and walked along the row of doorways, sticking her head into each in turn and sniffing the air experimentally. At the third door she stopped and stood on the threshold, peering into the blackness inside.

"Can't see a thing," she said. "But I think there might be something in here we can use."

"Do you need light? I think I have some matches," said Albers, and began groping at the pockets of his smock in search of them.

"Ah," said Ace, biting her lip uncertainly. She put a hand on his arm to stop his searching. "We're looking for explosive chemicals, so . . . no. Professor?"

The Doctor nodded and started rummaging through the pockets of his coat, taking out and then putting back a succession of objects including a yo-yo, a harmonica, a bag of boiled sweets and a pair of spoons before finally producing a small flashlight which he passed to Ace. She clicked it on and went into the storeroom, playing the light over the shelves lining the walls.

"Nitric acid, hydrogen peroxide, ammonium nitrate . . . there's some good stuff in here Professor," called out Ace. The light from the torch that spilled out of the door bobbed about as she inspected the contents of the room. "If we had more time I could cook up something really special with this lot."

"Time," replied the Doctor, "is the one ingredient we don't have. If I'm right the alien won't leave its base unguarded for long. You've got," he said, consulting a fob watch that he produced from his waistcoat pocket, "ten minutes. Do what you can."

"Right-ho Professor," said Ace and started taking a selection of tins and bottles from the shelves.

"Sir," began Albers and then stopped. "Professor," he began again.

"It's Doctor, not Professor," interrupted the Doctor testily.

"But she calls you-"

"Yes, she does," sighed the Doctor. "And believe me when I say that her wilful refusal to call things by their proper name is one of the least annoying things about her." He leaned his head into the doorway of the room where Ace was working. "See?" he called to her. "You set a bad example."

"Sorry Professor," called back Ace.

The Doctor shook his head and tutted in mock exasperation, rolling his eyes theatrically. He looked back at Albers.

"You had a question you wanted to ask me?"

"Well," said Albers. "It's just . . .you're entrusting a girl with making explosive charges. Does she know what she's doing?"

The Doctor snorted derisively. "Ace is to explosives what Leonardo da Vinci was to paint brushes. The girl is a pyrotechnical artiste. She could blow your hat off without your hair knowing a thing about it." He frowned. "A prodigious, if lamentably destructive talent that I have every intention of discouraging . . . the moment it stops being so damned useful."

After a few minutes Ace emerged from the storeroom carrying what looked like four tins of paint, two in either hand which she put on the floor beside the satchel containing the TNT. She knelt next to the satchel and started removing the charges and stacking them next to the tins. After they were all unpacked she looked up at the Doctor expectantly.

"Sticky tape?"

"Right," said the Doctor and commenced another search of his pockets. This time he unearthed a comb, a small rubber ball, more spoons and a dog-eared paperback copy of The Jungle Book before finding a small roll of masking tape and passing it to Ace. She divided the stack of charges into four piles and then proceeded to pack each pile around one of the tins, fixing them firmly into place with the tape. When she was finished she carefully placed the resulting four bundles into the satchel and laced it shut.

"Ready?" asked the Doctor.

"Ready," said Ace. She rose, lifting the bag with some effort and then led them to the stairs at the end of the corridor. They climbed the steps in silence and emerged from the door at the top into the concrete apron separating the two factories. The ever-present thunder of war continued to rumble on the horizon and the humming of aircraft engines cruising out of sight above the clouds seemed more numerous than before. Mindful of the volatile contents of the bag over her shoulder Ace led them towards the building on the left at a brisk walk, placing her feet with care on the cracked and uneven surface.

When they reached the wall they went to the row of head-height windows and peered inside. Everything seemed to be just as it was when Ace had been here last. Silence hung heavy over the interior and there was no sign of life apart from the regular blinking light from the device attached to the central pillar.

"Come on," said the Doctor after a few moments. "We don't have long. Let's find a way in and get those charges set up." He hurried alongside the wall to the nearest corner and, rounding it, saw that the wall on that side ran for over a hundred metres. There was a door set into the wall about twenty metres along it and they went to this and stepped inside, the Doctor leading the way. Their feet crunched lightly on the thin carpet of grit and glass fragments covering the concrete floor.

To Ace the web of cables that hung throughout it gave the huge volume an oddly confined feel compared to the similarly sized building from which she had retrieved the explosives earlier. The network of hanging lines strung from the exposed steel girders high above that criss-crossed the interior felt strangely oppressive and she was reminded again of a spider's nest. Let's hope the spider isn't home she thought and shivered, remembering her encounter with the creature in the tunnel.

The Doctor led them to the base of the central pillar directly underneath the winking red light suspended on its side high above and stood there, head craned, inspecting the web of cables. If he noticed the collection of human skulls attached to the column just above head height then he gave no sign.

"Hmm," he said, rocking on the balls of his feet and swivelling back and forth as he traced the course of the lines. "Yes . . . nearly complete I should say."

"It's not finished then? It hasn't sent its signal?" asked Ace.

"Oh, its finished enough to send a signal alright," replied the Doctor, still looking up at the cables. "But to get the sort of range I think our friend will be aiming for it'll need one or two more connections. Maybe just one." He looked at Ace. "Looks like we got here just in time. Start setting the charges." He looked up again at the device on the side of the column above them and rubbed his chin thoughtfully with one hand. "I'm going to see if I can get a closer look at that pulse modulator, just in case a Plan B is required."

"Right. Come on," Ace said to Albers. "You can help me with these." She put the satchel on the floor and undid the flap and took the bundled charges from it one by one, placing them with great care on the floor. She picked one up and passed it to Albers, who handled it as if it might bite him.

"Take this and place it up against the base of the wall in the far corner," said Ace, pointing to indicate which corner she meant. "Make sure it's right up against the wall."

"Alright," said Albers uncertainly and began walking very slowly towards the far end of the building. Ace picked up another of the charges and set out for the opposite corner.

Once he was sure that Ace was walking away from him the Doctor stepped up to the base of the pillar just below the clump of skulls. He took one last look over his shoulder to make sure Ace wasn't looking and then reached up and grabbed the lowest of the skulls, testing the strength of its attachment until he was sure it would hold his weight and then pulling himself up. With surprising agility he began clambering up the rusting pillar, using the skulls as hand- and footholds. When he had climbed past the band of skulls he began grasping some of the large boltheads studding the surface of the column and he pulled himself up by these until he reached the level of the device. It was about the size of a shoebox and made of some matte-black material that seemed to absorb the faint shards of light falling through the windows high above and made the slowly pulsing red light at the centre of it all the more vivid. With his legs wrapped around the pillar as firmly as he could manage and one hand tightly gripping one of the rust-red bolts he used his other hand to pry open the cover of the pulse modulator and then peered at its insides. A status display screen scrolled line after line of alien symbols and the Doctor studied this for a few minutes, his brow furrowed with concentration.

"Well well," he said quietly. "E.T.'s calling home is he? Let's see what we can do about that."

He began tapping out commands on the keypad underneath the screen, hesitantly at first but then with increasing confidence as he went on.

o o o

The hunter returned to the site through the mouth of the waste tunnel by which it had left and strode through the echoing chambers of the basement. It bore a fresh length of wire wound in coils and draped over one shoulder, one frayed end trailing along the ground after it like a tail. It had acquired the last length of cable that it required for the transmitter with ease, ambushing a small troop of humans escorting one of the cable-carriers through an alley less than half a kilometre from the factory. The focus of the fighting seemed to be moving steadily closer to the site and it would only be a matter of days now before it came close enough to jeopardise the transmitter. Stray salvoes of artillery had been falling close enough to shake the building's foundations for the last couple of days now and it couldn't be long before one side or the other targetted it deliberately as the wavefront of their conflict burned across the face of the city like a forest fire. It had seen enough of the humans to know that they would destroy their own creations utterly and without hesitation rather than see them fall into the hands of the enemy.

No matter. Once the transmitter was completed and the message sent it would only be a matter of time before-

It stopped mid-stride and mid-thought as a string of warning lights lit up on its head up display, blinking into life one after another. Its sensors reported the vibrations of movement in the building above, the elevated carbon dioxide levels of multiple prey-contacts and the unmistakeable scent of chemical explosives.

Inside the site.

Bellowing with rage it shucked the coiled cable from its shoulder and set out at a dead run, pounding heavily up the steps that led towards the ground floor.

CHAPTER FIFTEEN

Ace knelt to lay the charge very gently on the floor against the wall and then rose and took a step back. She glanced towards the far corner to check that Albers had placed his charge correctly but she couldn't make him out in the gloom that lay over the far reaches of the giant room.

She turned back to the wall in front of her and appraised it with a professional's eye, gauging its thickness and strength and reassuring herself that her modified charges would be sufficient to bring it down. She thought longingly of the stock of chemicals remaining in the storeroom below, thinking what she could have made of them given more time. Another couple of hours, she thought wistfully, and I could have made a bomb that would have put this place into orbit.

She sighed and looked again at her jury-rigged charge. When she had made them earlier she had been quietly proud of her efforts, given the limitations of time and materiel imposed on her, but now when she looked at it she couldn't help but compare it unfavourably with what could have been. Oh well, she thought. Not my best work, but it'll just have to do.

She was still looking at her creation with a lingering sense of disappointment when she heard the crisp metallic click of a gun being cocked, directly behind her head.

o o o

The Doctor entered the final few commands into the pulse modulator's control panel, snapped the cover closed and then began shinning down the column. When he neared the bottom he jumped lightly to the floor and then stood and brushed at his coat with both hands, tutting at the twin streaks of rust left by the edges of the pillar.

He looked around for the others and saw Albers walking briskly back across the factory floor towards him. He looked towards the far corner, searching for Ace.

And saw her, standing with her hands raised facing the rag-wrapped figure pointing a gun straight at her head.

o o o

"Peter," said Ace, trying to sound calm. She slowly raised her hands, palms open. "What are you doing?"

Peter's face was bone-white underneath the layer of grime. Tears welled in the corners of his eyes. He held Albers' pistol out before him with both hands.

"You can't do it," he said in a trembling voice. "I won't let you."

"Peter," began Ace.

"I won't let you!" shouted Peter. The muzzle of the pistol wavered erratically in his shaking hands. Tears began to fall from his eyes, scoring white lines through the dirt on his face.

"Why can't you just leave her alone?" he sobbed. "She's not doing anyone any harm."

Not strictly true, thought Ace, images of the bodies of Albers' men lying in the tunnel and of the clutch of skulls sprouting from the central pillar flashing through her mind, but probably best not to bring that up right now.

She heard the slapping sounds of approaching footsteps on the bare concrete and took her eyes from Peter long enough to see the Doctor and Albers running towards them across the factory floor.

"Peter!" yelled the Doctor. "Put the gun down!"

Peter threw a quick glance at the approaching figures and then turned back to Ace. He blinked away tears. The gun in his hand slowly steadied, levelled at Ace's head.

"I'm sorry," he said in a small voice. His hands tightened on the pistol. "I'm so sorry."

Three red points of light in a triangular formation appeared on his chest and moved slowly upwards. For Ace time seemed to slow down and she watched in silent fascination as the pattern of lights played across his throat and settled on the side of his head. Laser targeting, she thought numbly. That's laser targeting.

"Peter," she said urgently.

"I'm so sorry," said Peter again, his voice squeaking. He slowly pulled back the trigger.

"Peter!"

Then there was a tearing sound, a sudden wash of heat and a flash of green light and Peter's head exploded in a wet spray of brain and bone.

o o o

The Doctor felt the plasma blast scorching past him as he and Albers ran the final few metres towards Ace, saw it strike Peter and watched his headless body crumple to the floor like a puppet whose strings had been cut. He whirled about in search of the source of the shot, scanning the shadows and caught the flickering of light of a second shot being fired just in time to reach out and push Albers to the floor. The energy burst ripped through the space where Albers had been standing and struck the wall behind him with a muffled thump, sending out a great cloud of dust and fragments of brick and stone.

"Take cover!" yelled the Doctor, scurrying behind the nearest pillar and pressing himself hard up against it. He saw Albers scrambling to his feet and diving behind another pillar ten metres away as a further flurry of shots flew out of the shadows from the far side of the room. Where they struck against the metal pillars the blasts erupted in showers of molten metal, sprays of red-hot sparks cascading from the impact points ike bursting fireworks.

The Doctor looked over to where Ace sat, crouched at the base of another pillar and saw her flinch as more energy blasts smacked against it. The stink of burnt metal competed with the smell of plaster dust to fill the air.

"The bomb!" shouted the Doctor to Ace. She looked over at him and saw him pointing towards the explosive charge that she had placed against the wall not ten metres from where she now crouched.

"The creature sees by thermal imaging!" shouted the Doctor, cupping his hands to his mouth to be heard above the noise of another volley of plasma fire. "If we can set the bomb off between us and it then we might be able to escape while it's blinded by the flash!"

Ace quickly ducked her head around the edge of the pillar and just as quickly drew it back as another green energy burst flew past close enough for her to feel the heat of its wake. She looked in frustration at the charge laying against the wall, so close to her and yet out of reach.

"I can't get to it Professor!" she yelled to the Doctor. Another plasma blast struck the column she was sheltering behind and sent a shower of hot sparks flying over her. She shrank into a ball and squeezed her eyes tightly shut as more shots smacked into the floor by her side, gouging deep smoking pits out of the concrete where they struck.

When she opened her eyes again she saw Albers running past her, arms and legs furiously pumping. The glowing green fire of plasma blasts tracked his progress, some missing him only by centimetres and passing close enough to leave smouldering burn marks on his smock. He ran to where the explosive charge sat against the wall, scooped it up without slowing and then turned and ran back towards the centre of the building, heading for the unseen source of the energy blasts.

"Albers, wait!" cried the Doctor as he saw the man running past him.

Albers weaved as he ran headlong into the darkness, dodging the hail of shots that zeroed in on him for a full twenty metres before a single blast took him full in the chest, setting off the explosive charge in a tremendous detonation that for a brief moment seemed to fill the whole of the vast room with fire.

Crouched behind their respective pillars, the Doctor and Ace were protected from the full impact of the blastwave but they felt the edges of the furnace blast of heat that accompanied it and saw the huge wash of blinding white light. The sound of the blast filled the space with a thunder that echoed throughout it for long seconds. The sudden silence that followed was filled with the tinkling sound of falling glass as the building's few remaining windows fell from their frames in jagged shards.

Rising to his feet the Doctor ran to where Ace crouched, grabbing her arm and pulling her up.

"Move!" he cried and together they ran stumbling towards the door.

o o o

The burst of heat from the explosion flared in the hunter's visor like a sunrise, washing everything else from view in a pure white glow that filled its field of vision. It silently cursed as the remaining prey-beasts faded from sight and hurriedly slapped out the sequence of commands on its forearm control panel that switched the visual spectrum from thermal imaging to ultraviolet. As the new filter clicked into place it swept the building, searching for the two remaining targets.

And found them, running headlong for the door.

o o o

The Doctor and Ace burst out of the door onto the street outside. A low bank of rubble sat across the road from them and they hurried towards it at a crouching run. Ace ran straight over the top of the piled debris, loose bricks clinking under her feet, and jumped down into cover behind it. The Doctor was close behind her, but instead of dropping down behind the banked rubble with her he stopped and stood atop it and turned back towards the factory.

The creature stood silhouetted in the doorway, its camouflage disengaged. The flickering light of small blazes set off by its weapons fire glowed from within the building, reflecting dully from the dark carapace of its armour. It saw the Doctor standing on top of the heaped ruins across the road and let out a bellowing cry of rage. The plasma weapon on its shoulder swivelled to target him.

The Doctor's head tilted back as if listening for some distant sound and then he lowered his head and glared back at the armoured creature, framed in the doorway and backlit as if by the fires of hell. His face twisted into a triumphant snarl.

"Hunting season," he hissed through clenched teeth, "is over."

And then there was a furious roaring sound above them that suddenly rose in pitch and the factory disappeared in a blinding flash and a roar that sounded like the ending of the world.

CHAPTER SIXTEEN

When Ace came to her senses she found herself lying behind the rubble heap, covered in a thick film of grit. She sat up slowly and looked around, blinking away the dust in her eyelashes and coughing. Her ears rang with a high-pitched tone. She saw the Doctor laying nearby and as she watched he sat up and began brushing brick fragments off of his jacket with his hands.

Where the factory had stood there was now only a giant ring of rubble, a circle of shattered bricks and twisted girders surrounding a huge smoking crater. A series of faint clacking sounds came from within as the ruins sagged and settled.

"What just happened?" asked Ace weakly, brushing showers of dust and small fragments of concrete out of her hair with her fingers.

"Plan B," said the Doctor simply. He got to his feet and regarded the remains of the building with a satisfied smile. "I had a feeling that we might not have time to destroy the transmitter before the creature returned, so I made a little adjustment to the signal it was planning to send and then set it to transmit. As I said, even with the transmitter incomplete there was still enough power in the signal to reach any receivers within a hundred miles or so."

"What did you change the message to?" asked Ace.

"I simply set it to transmit the map co-ordinates of the factory," replied the Doctor, idly brushing more stone fragments from the lapels of his coat with the back of his hand. He looked again at the ruins. "From the looks of it both the Germans and the Russians opened fire on it at the same time."

"But," said Ace, struggling to her feet to stand beside him, "how did you know that they'd think it was the location of a target?"

"A set of map co-ordinates, broadcast uncoded?" snorted the Doctor. He waved a hand towards the horizon, where pale plumes of smoke and the far-off whistle of falling artillery shells marked the progress of the battle raging through the city. "In this madhouse it'd hardly be an invitation to a picnic, now would it?" He smiled at her kindly. "Now come on," he said. "Time we were leaving."

o o o

They walked back through the streets of the ruined city in silence. Once on their route they spied a group of grey-clad soldiers picking their way through the rubble heading eastwards but they avoided them without difficulty and made their way back to the TARDIS. When they rounded the last corner and saw the dust-coated light peeking through the top of the pile of brick and concrete Ace remembered the reason she had left the Doctor lying there and gone looking for help in the first place and her heart sank.

"How are we going to shift that lot?" she said despairingly. She remembered the chemical treasure trove in the storeroom and contemplated retracing their steps to find it without enthusiasm.

"Nil desperadum Ace," said the Doctor, striding briskly up to the pyramid of rubble encasing the TARDIS. He circled it for a minute or so, standing on tip toe and stooping and craning his neck to scrutinise it from all angles.

"Pardon?" said Ace.

"'Nil desperandum'," replied the Doctor, still peering at the piled debris. "Latin for 'do not despair'." He shook his head and tutted. "What do they teach young people in schools these days? You see Ace," he continued, "as with any problem, it's simply a matter of applying pressure . . ." He reached out, put one hand on the end of one of the concrete beams sticking out of the pile and gave a small push. There was a short pause and then one side of the heaped rubble wobbled and then avalanched outwards in a tide of stone and scree, revealing the upper half of the TARDIS door.

". . . in the right place," he finished, beaming with satisfaction. He stepped forward over the fan of debris that had fallen away, stooped and began pulling free the larger pieces of concrete obscuring the foot of the door.

Show off, thought Ace.

"Professor," she said, joining him in clearing away the last pieces of concrete. "What was the alien's message? The one that you changed."

"Ah," said the Doctor. "The message. Yes." He picked up the last of the large stones and heaved it aside and then started sweeping the bank of smaller pieces away from the door with his foot. "It was a very simple message. Just one word in fact."

"What word?"

The Doctor paused for a moment before answering. "Help."

"Help?"

"Yes."

"You mean it wasn't the scout for an invasion after all? It was just trying to get home?" said Ace indignantly.

"My guess would be that it came here on some sort of hunting expedition, a sort of human safari if you will, found it had bitten off a bit more than it could chew and then got stranded here. Perhaps its spaceship was damaged in some way in the fighting." He shrugged. "Who knows?"

"But if it was just trying to go home then-"

"It travelled thousands of light years to come here and hunt human beings to make decorations out of their bones," the Doctor reminded her sharply. "Any sympathy that you might be tempted to feel for it would be better reserved for its victims." He fixed her with a stare. "It had to be stopped, Ace."

Ace thought about this. "I suppose so," she said. She made a face. "What kind of creature would hunt intelligent beings for sport anyway?"

"You're English," said the Doctor with a twinkle in his eye. "Ask a fox." He groped in his waistcoat pocket and produced the TARDIS key and put it into the lock.

"Time to go," he said, turning the key and swinging the door open. The warm light of the TARDIS interior shone out from within.

"You were wrong about one thing Professor," said Ace as the Doctor went to step into the TARDIS. He stopped and turned to face her.

"What's that?" he asked, frowning.

"When you said that this was something that shouldn't be witnessed," replied Ace. She looked out over the city one last time, taking in the crumbling ruins around them and listening to the distant sounds of war drifting towards them over the broken rooftops. "Everyone should see this," she said quietly. "Then maybe it wouldn't happen again."

"Ha!" barked the Doctor. "Fat chance. If there's one thing that human beings excel in, it's repeating past mistakes. If you think this is bad," he continued, turning and stepping into the welcoming brightness of the TARDIS control room, "you should see the Battle of Yerevan." He looked out through the doors and sniffed. "Makes this look like a theme park by comparison."

"Yerevan?" said Ace, stepping through the door. "Where's that?"

"Late twenty first century Persian Caliphate," said the Doctor. "What you'd call Iran, in your time." He went to the console and began pressing buttons. "I could show you, if you like."

Ace pushed the door shut behind her. Her last words drifted out of the TARDIS before it closed and hung on the chill afternoon air as the blue box's image wavered and shook and then disappeared.

"Do they have a Burger King?"

THE END

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