"Wh… what?" Donna gasps. "How can that be?"
The Doctor isn't listening. He reaches into his pocket for the sonic, his eyes glued to the advancing insect horde as he slowly draws the device out and slides a seldom used switch to a setting he's only used twice before, the maximum disassembly setting.
He risks a quick glance at the sputtering environmental converters above their heads, frost covered metal boxes with icy grates nestled between the rows of flickering UV lights. If he takes one of them out, it would set up a chain reaction throughout the base. The tentative mix of heat and oxygen will dissipate as the condensers fail one by one and the planet's poisonous atmosphere once again takes over.
If he's very lucky, it'll force the creatures back into hibernation. Of course that would also mean no oxygen for him to breathe, but the portable regulator Donna's wearing should last for several hours yet. She and the baby will be safe, which is all he really cares about. Although safe is a relative term he supposes when being stalked by a horde of giant insects.
He frowns slightly at the thought, his eyes returning to the skittering hybrids as he slowly draws in several foul tasting breaths, building up his oxygen reserves before the condensers go offline and his body reverts to respiratory bypass to survive.
"When I tell you to run," he whispers into Donna's ear, as they pull up short against an icy lab table, "we run, and we don't look back until we reach the TARDIS."
"We're…" Donna gasps fearfully, "we're just going to leave?" She swallows, licking her lips as if nauseated, "but they were human once. Isn't this the moment when you usually try to reason with them? Offer them your help?"
"They're beyond help Donna," he says grimly, "beyond reason. It was already far too late for that by the time they decided to infect themselves."
"Infect themselves with what?" Donna asks, trembling behind him as the creatures advance.
"A retro-virus," the Doctor says, holding the sonic out like a beacon before him, waiting for just the right moment to use it. "They were attempting to improve on the human condition by augmenting it with a mixture of Terran and alien insect DNA."
"You have got to be kidding me," Donna gasps, "who does that?"
"Someone desperate to win a war," the Doctor says coldly, his thoughts briefly turning to his own people and what they'd nearly done in the name of winning theirs."They were attempting to genetically engineer the ultimate soldier," he says, "only they got more than they bargained for. The virus they created didn't enhance their humanity, it stole it. It spread from one colonist to the next like wildfire, overwriting their DNA into something mindless. A living extension of the virus itself," he says, indicating the infected research team with a tilt of his chin, "a walking virus with just one single unwavering purpose; self-replication."
"The stasis pods," Donna murmurs, her pale face lighting with sudden understanding, and the Doctor nods.
"Built to contain the infected while they worked on a cure. A cure they never found apparently."
"Then that... stuff inside..."
"Human," the Doctor says with a grimace, "like a snake, shrugging off its skin."
"Oh my God," Donna nearly gags, her hand covering her mouth, "but… but I don't understand," she murmurs, her face pale with shock, "they called for help."
"No," the Doctor says. "They didn't."
He aims the sonic at the oxygen converter directly over their heads and activates it suddenly, unleashing an unholy wall of sound like the roar of a thousand jet engines echoing back at them through the tunnels. Donna yelps, her hands flying to her ears, but the Doctor just stands his ground, gritting his teeth as every connection holding the converter in place abruptly comes undone and it explodes in a shower of sparks, taking a good portion of the rough hewn ceiling with it.
"Run!" he cries, taking Donna's hand and heading for the doorway amid a shower of falling ice chunks and insect hybrids.
"What do you mean, they didn't," she gasps as they quickly wend their way back through the partially obstructed tunnel, "we answered their distress signal didn't we?"
"It wasn't a distress signal," the Doctor says, proud of her for needing an answer to the question, but slightly exasperated that she's asking it now, "it was a warning beacon. Over the years the accompanying message to stay away became increasingly garbled, until finally only the beacon remained."
"And I insisted you answer it," Donna says, contritely.
"You couldn't have known," the Doctor says, glancing back over his shoulder at the angry insect hybrids just beginning to emerge from the doorway at the other end of the tunnel. He'd timed the explosion to go off just as the majority of them had reached the converter, but hadn't counted on their ability to recover quite this quickly.
"Come on," he urges Donna, his fingers curling tightly around her wool encased hand as he helps her past the icy outcropping at the mouth of the cave-in. A whining insect drone mingles with the roaring wind echoing through the tunnel and she blanches. "Don't look back," he says, "just run."
They pelt back up the permafrost coated tunnel as quickly as they can. Lights flicker and fade into darkness as the environmental systems grind to a halt and the freezing wind tugs at their backs with icy fingers. The whine of a dozen giant hybrid insects fills their ears and Donna stumbles, her knees going weak. The Doctor grimaces, wrapping his arm around her shoulder and forcing her to keep moving forward.
"How did it spread," she gasps, tears seeping from her eyes from fright or hormones or possibly just the cold, "the virus. You said it spread like wildfire. How did it?"
But before he can form the words, they're suddenly struck from behind. A hard black body slams into the Doctor and he sprawls onto his stomach, Donna tumbling from his grasp. He struggles, scrabbling at the slippery ice in the growing darkness trying to regain his feet. Reticulated black limbs covered in stiff bristly hairs pierce the ice like grappling hooks around him and he tenses defiantly, struggling to lift his head and free himself of the crushing weight.
His eyes fall on Donna's crumpled figure in the dimness, surrounded by undulating insectoid bodies, her brilliant red hair like a silken waterfall spilling from the confines of her tattered hood.
"Donna!" he cries, his hearts leaping into his throat when she doesn't respond.
The hybrid insect pinning him slices through his anorak like butter, rending the tattered pieces from his body with dripping black claws. Through sheer force of will, the Doctor manages to climb onto his hands and knees and start crawling towards Donna's motionless body. The quivering creature yanks him back, the Doctor's outstretched fingers raking long trails in the frost slicked ground as he groans in frustration.
"Do you mi..." he starts to growl before something long and sharp pierces him between the shoulder blades and the breath abruptly goes out of him.
Burning venom spreads like hot magma pulsing outward from the wound, and he tries to scream, his body trembling like a butterfly caught on the head of a pin. Every nerve ending erupts in hot liquid pain and the scream dissolves into a gurgling whimper, his senses shattering as his mouth fills with something bitter and his vision starts to crumble around the edges.
He's only vaguely aware of the creature releasing him, his body convulsing once as it withdraws its stinger and he falls, twitching feebly to the icy ground. His failing eyes find Donna's unmoving form in the darkness. I'm sorry. I'm so sorry, he briefly thinks, before all thoughts vanish in a burning haze of pain. His chin sinks to the frosty ground and blessed darkness claims him.
"Are you awake?" Donna whispers in the darkness, the two of them wrapped up in bed together. The Doctor's arm is draped over her hip as she spoons naked against him.
"Yes," he says simply and she rolls over onto her back, gazing up at him as he props himself up on one elbow to look at her. His eyes play over the languid curves of her body, lingering for a moment on her shapely breasts.
"What are you thinking about?" she asks, reaching up to caress his stubble covered cheek, her thumb lightly tracing the outline of his lips.
"You, mostly," he says, taking her hand and planting a feathery soft kiss on her palm.
"Mostly?" she asks, one eyebrow cocking slightly when his smile falters almost imperceptibly. "It's been two weeks since we found out and you haven't said a word about it since. It's not like flu you know. There's no such thing as a temporary case of pregnant."
His mouth quirks slightly at that. "I know," he says softly.
"I thought you were happy," she says.
"I was," he says firmly. "I am. It's just…" he breaks off with a sigh and thoughtfully scratches the back of his head. "It's been a long time since I became a father the old-fashioned way Donna," he says, his smile turning wan, "since before the time war. I'm not sure I even remember how."
"You do," Donna tells him, her tone reassuring. "I saw how you were with Jenny in the end. You would've been a good father to her."
He frowns, his forehead puckering as he rolls onto his back and stares up at the roundel covered ceiling. "Yes, and look at how well that turned out for her," he says flatly.
"You can't blame yourself for what happened," Donna says, turning onto her side to rest her head against his chest, her silky hair tickling his skin.
"No?" he asks, his eyes flickering to her face. "Who then?"
"Umm, how about the nutter holding the gun," Donna says flatly and though her argument is technically true, it does little to ease the Doctor's guilty conscience.
"Don't borrow trouble my mum always says," Donna tells him, her hand sliding up his bare chest to cover one of his hearts. "people still have free will you know. You can't hold yourself responsible for every bad decision they make in your presence."
"No," he agrees somewhat reluctantly, "but I can hold myself responsible for the ones they make as a direct consequence of my actions. You heard what Davros said about me. I take ordinary people and I fashion them into weapons."
Donna rolls her eyes. "Oh right, so we're listening to Davros now, because he was, you know, such a picture of mental health," she mutters sarcastically.
"Just because he was mad doesn't mean he wasn't speaking the truth, Donna," the Doctor tells her.
"It doesn't mean he was either," Donna insists.
"You're the one who accused me of turning Martha into a soldier remember," he says.
"Well, I didn't mean it like that," she snaps.
"You weren't wrong," he says, shame colouring his cheeks, "and neither was Martha. I'm like fire. I burned her and I burned you, I couldn't live with myself if I wound up burning the baby as well."
"That's not what you do," Donna says, her storm coloured eyes locking with his. "You don't burn people. You inspire them to find the best in themselves just by believing that they can."
"I inspire them to lay down their lives," he says bitterly.
"Maybe that's just human nature," Donna says, "maybe if you inspire us to overcome our inherent weaknesses, then what remains is selfless."
"I never wanted that sort of responsibility."
"Really," Donna says flatly, "because from where I'm sat, it kind of looks like you do."
"What's that supposed to mean?" he asks sharply.
She frowns at him and abruptly sits up. "It means you're not God," she says, "so stop trying to act like it. Time Lords are so much bigger than the rest of us is that it? Your big fat heads are far too complex for our tiny human brains to understand, well in case you hadn't noticed, I didn't fall pregnant and suddenly forget who you are you know. It isn't as if I expected you to give up traveling or demanded that you abandon the TARDIS for a country house in Heathfield Court." She blinks and swallows suddenly. "Now if you'll excuse me, apparently I sat up too quickly and have to go throw up now," she says. "Feel free to take as much blame for this particular consequence as you like."
With that she bolts from the bed, the silken sheets falling away from her naked body as she runs for the bathroom and slams the door shut behind her. The Doctor sits up, grimacing slightly at the sounds of retching coming from the closed room. He plucks his pyjama bottoms from the floor where they lay in a puddle of hastily removed clothing by the side of the bed and shrugs them on as the toilet flushes.
He stands there for a moment, watching the still closed door expectantly. Five minutes later Donna still hasn't emerged, though the room has lapsed into silence. He gives the doorknob an experimental turn and finds the door unlocked. He pushes it open to find her perched on the toilet seat, slowly sipping water from a paper cup.
He leans against the doorframe, watching her in silence as she intentionally avoids making eye contact with him, her renaissance curves already beginning to blossom with the first signs of impending motherhood. She's never looked more beautiful he thinks, her luminous skin glowing with the promise of the brand new life growing inside of her.
"Is that what you wanted," he asks softly, "a country house in Heathfield Court?"
Donna frowns into her flower embossed cup as if the water inside has suddenly turned bitter, "I could have had that with Shaun," she says flatly. "You came back and I left him for you." She looks up at him suddenly. "What does that tell you?"
One side of the Doctor's mouth quirks into a wan smile. "That I really don't deserve you," he says.
Donna nearly smiles at that. "So my mum keeps telling me," she says.
He walks into the room and Donna impulsively threads her fingers through his as he takes a seat beside her on the edge of the bathtub.
"For the record, I would never try to buy my own happiness at the expense of yours," she tells him.
"I know," he says simply, his thumb tracing light trails over the back of her hand.
"I never expected you to change for me," she says.
His mouth quirks slightly at that. "Did I ever tell you why I started traveling Donna?" he suddenly asks her.
"I…" Donna blinks, slightly thrown by the unexpected question. "I suppose I always just assumed it had something to do with your adolescent addiction to adrenaline."
"No," he says, one eyebrow quirking wryly, "that wasn't it. It was because I needed to find something that the Time Lords lost a long time ago."
"What like buried treasure, you mean?" Donna asks, and he can practically see the moment when she turns him into Indiana Jones inside her head.
"Ourselves," he says, smiling a little despite himself, "We were just like human beings once you know, in the beginning. So full of passion and conviction, but then we evolved. We harnessed the vortex and it changed us..."
"It stagnated you," Donna guesses and the Doctor nods.
"Somewhere along the line we traded our humanity for, I don't know. Knowledge. Power. Arrogance maybe. After a while, it was all we were. There was nothing else."
"But, you were different," Donna says.
"No Donna," the Doctor says ruefully, "that's just the point. I wasn't. Not really." His fingers tighten around hers. "You said you never expected me to change," he says softly, "but you have changed me. All of you have. All the human beings I've traveled with through all those regenerations helped me rediscover the humanity I'd lost. I should have realised it would just be a matter of time before the change would be significant enough to…" he breaks off, his eyes straying to her thickening waistline.
"Make the impossible, possible," Donna murmurs thoughtfully, her fingers spreading over her belly.
"I lost everything I had in the blink of an eye," the Doctor says, his fingers covering hers, "everything I cared about. Now I'm on the verge of building something just as good with you and I'm…" he breaks off, his voice cracking as he swallows past the sudden lump in his throat, "I'm…terrified that it will be ripped away from me and I'll end up losing myself all over again."
"I'd never let that happen Spaceman," Donna tells him emphatically, her hand disengaging from his to caress his face. "The stakes are higher now it's true," she says softly, her fingers raking soothing trails through his hair. The Doctor closes his eyes, his forehead falling against hers. "It's not just you anymore," she murmurs. "You've got more to lose now, but that just means you've got more to live for as well. We both do. Isn't the chance of holding onto that worth the risk?"
The Doctor's mouth quirks into a fleeting smile and he kisses her suddenly, Donna's soft lips parting beneath his. She tastes of mint mouthwash and cherry lip balm and human kindness.
"I'll take that as a yes," she gasps, throwing her arms around his neck to answer his kiss with one of her own.
He hears something. The wind screams in his ears, settling into his bones with a numbing ache and he can hear a soft keening somewhere in the background, like a wounded animal whimpering in pain. He opens his eyes, blinking spots. A rasping groan echoes back at him from shadowy walls he can't see through the darkness. It takes him a moment to realise the sound is coming from him, his throat aching and raw with the strain of it. Tiny frozen daggers pelt him in the face, rifling through his hair like talons and he stops groaning, his mouth full of something viscous and bitter. He gags, clutching at the frost covered earth with numb fingertips. He lurches onto his side to spew something blacker than the pitch black darkness all around him onto the ground.
The Doctor lays there trembling for a moment, the icy wind cutting through him like a knife. Something that feels like a hot coal is slowly burning its way through his back between his shoulder blades, burrowing into his chest like a hot drill. He blinks, his eyes blurry and sore. He flops back onto his back, shuddering with the sudden jolt of pain that passes through him like a lighting bolt. He swallows and grits his teeth against the bile rising in the back of his throat. Reaching into his overall pocket with grimy trembling fingertips, he pulls out something that looks like a large multifaceted crystal doorknob.
He presses a switch at the base of the crystal and a bright white beam of light springs from it, increasing in intensity until he's forced to avert his eyes. The light continues to flare until the darkness is banished, then fades back to a more comfortable level. He groans, blinking sunspots, startling suddenly when he abruptly notices the giant hybrid insects hanging in a tangled clump not three feet above his head.
He swallows, warily turning his head to squint at something blurry and orange laying in a crumpled heap near the mouth of the chamber. At first he thinks it's the remains of his anorak, until he spies the matted ginger curls tumbling from the hood.
"Donna!" he gasps, both of his hearts immediately pounding in his ears. He lurches onto his hands and knees, blinking stars as his head starts to swim. The not quite immobilised creatures covering the chamber's low-hanging ceiling twitch feebly in the gradually altering atmosphere as he crawls over to her.
"DonnaDonnaDonna," he babbles hoarsely, the words tumbling from his mouth in a panic as he eyes the dark blood seeping sluggishly from a gash at her scalp. It slides in a thin rivulet down the virtual mask still covering her face to the permafrost covered ground. The Doctor swallows, his hearts hammering in his ears as his trembling fingers check the pulse at her neck.
He nearly collapses with relief when he locates the reassuring rhythm of her slightly elevated heartbeat. He examines the wound at her scalp, brushing her sunset hair back to reveal a shallow gash and a bruise discolouring her brow, bloody, but thankfully not life-threatening.
He shudders, nearly breaking down, blinking tears as his eyes close. His trembling fingers spread to caress Donna's face as his mind reaches out to check on the baby. He's only able to manage the briefest moment of contact before losing his concentration, his misfiring nerve endings smouldering like burning embers beneath his skin, but it's enough to establish that the baby too is unharmed.
The Doctor sags, his grubby fingertips scraping the icy ground. He blinks, shaking his head, his senses fading in and out like painful strobe lights, blurring and sharpening and blurring again as the retro-virus begins to overwrite his DNA with its own.
He glances up at the quivering hybrids hanging over his head, their brittle shining bodies periodically convulsing in the diminishing atmosphere. He wonders how long they'd managed to hold onto their humanity before losing themselves completely to it.
Donna groans and the Doctor leans over her. "Easy," he murmurs softly, her eyelids fluttering for a moment before her stormy blue-green eyes open and focus somewhat sluggishly on his face.
"Is the baby all right?" she murmurs, her words a bit slurred as she weakly grips the collar of his pullover.
"The baby's fine," the Doctor reassures her, his grubby fingers closing over her mitten covered hand, "and so are you." He tries to smile as he helps her sit up, but the knowledge that this will likely be their final moment together keeps it from forming on his lips.
They share a brief embrace, Donna's gaze shifting from his face to the hybrid covered ceiling above their heads. To her credit, she doesn't scream, though her complexion visibly pales. "God," she breathes, her voice barely above a whisper, "are they dead?"
"Dormant," the Doctor murmurs back, "or very nearly," he says, shaking his head again to try and clear his vision. "The environmental systems have mostly failed, forcing them into hibernation to survive."
"How long can they stay like that?" Donna asks, studying the Doctor's face with some concern.
He swallows, his head beginning to throb as the virus races through his bloodstream, raising his blood pressure and constricting his blood vessels. "As long as it takes," he says, queasily licking his lips.
Donna swallows, warily eyeing the rough hewn chamber walls. "What, is this some sort of nest?" she asks.
"So it would seem," the Doctor nods, or an incubation chamberhe thinks, though he doesn't say it out loud.
The mouth of the chamber fades into utter blackness beyond the perimeter of the still softly glowing crystal. Donna eyes the emptiness apprehensively. "Do you have any idea where we are?" she asks.
"Not a clue actually," he says, his spatial sense blurring almost as badly as his vision.
"But, you can still find your way back to the TARDIS right?" she asks him.
The Doctor slowly shakes his head. "I'm not going back to the TARDIS Donna," he says, his voice cracking hoarsely on the words.
"Don't be an idiot," Donna says, her casual tone belying the sudden look of panic in her eyes. "Of course you're going back to the TARDIS."
"I can't leave Donna," the Doctor insists quietly, "I've been infected."
"No, that's… no..," Donna stammers, shaking her head, "but you're... you're immune right?" Her grip on the collar of his pullover tightens in desperation as her eyes fill with tears. "Please tell me you're immune!"
The Doctor shudders, his raw nerve endings erupting in a wave of exploding capillaries just beneath the surface of his skin. Donna's eyes widen in horror at the spontaneous bruises springing out all over his face.
"Don't think so," the Doctor says, trying to sound wry and failing.
"Oh my God," Donna whimpers. "No, but you can... you can find a cure," she insists tearfully, her hands balling into fists against his chest.
"No…" he says softly.
"Yes, of course you can," Donna cries, her trembling fists impotently pounding him now, "If anyone can find a cure, it's you."
"No, Donna!" the Doctor snaps, grabbing her hands in growing exasperation. A flurry of activity ripples through the semi-comatose hybrids above their heads and he grimaces, waiting for them to stop moving completely before continuing. "Listen to me," he says, his tone more subdued, "we're running out of time. Take the crystal and find your way back to the TARDIS."
"I can't…" Donna sobs miserably against him, big sloppy tears rolling down her cheeks.
"Yes, you can," the Doctor says firmly, "just concentrate on the TARDIS and she'll lead you to her. Once you're safe on board, she'll activate Emergency Program One and take you back home to Chiswick."
Donna's eyes flash angrily through her tears. "While you do what exactly? Just stay here and join the horde?" she snaps tartly.
"No," he says, his lips pressed together in a grim line, "I'm going to finish what the last human left here was trying to do when he blew out that tunnel. I'm going to destroy the base."
"That's your brilliant plan," Donna hisses, angrily swiping the tears from her eyes, "destroy the planet and kill yourself?"
"I've got no other choice Donna," the Doctor says, his entire body beginning to tremble with nerve imploding pain. "The virus was designed to adapt. That's what makes it so dangerous. Every time it replicates itself it incorporates the newest host's DNA into its viral matrix and it becomes stronger. Consuming a Time Lord would make it practically unstoppable. It would have Time Lord intelligence and the ability to regenerate. It would find a way to escape the confines of this planet and it would invade the universe like a black plague, spreading from planet to planet replicating itself until there was nothing left, but it."
"I don't care," Donna says defiantly. "I'm not leaving you here to die. Think of something else."
"Donna, please," he says, grimacing with pain, "we don't have time for this. If you lov-, care about me at all you'll do as I say and let the TARDIS take you home."
"Give me your hand," she demands and the Doctor blinks, momentarily confused.
"Donna," he grumbles, annoyed.
"Shut up," she snaps, "and give me your hand."
Reluctantly he lays his hand in hers palm up, his exposed finger tips swollen and waxy looking. She peels off his glove, then surprisingly unzips her anorak.
"Donna what are you..?"
"Shhh," she says, unfastening one of the Velcro braces holding up her overalls and lifting her pullover to expose a small portion of her swelling belly. She takes the Doctor's hand and lays it on her exposed skin, shivering slightly at its unexpected lack of warmth. He mumbles some sort of apology, but she just shushes him again and watches him with an expectant look on her face. That's when he feels it, three determined little thumps striking his hand in rapid succession.
"Was that a kick?" he asks, his throat constricting with a feeling he hasn't felt in so long, he's not even sure he can put a proper name to it.
"Yeah," Donna whispers, her own voice choked with emotion.
"When did this start?" he asks. So much time has passed since he's felt one of his own children moving beneath his hand, he'd literally forgotten what it felt like until this moment.
"It's a recent development," Donna says, tears beginning to seep from her eyes again. "That's your son," she tells him, her hand covering his. "and if you think I'm just going to let you roll over and die without even trying for a chance to see him grow up, you're crazy. So you come up with another plan Spaceman!" she cries, her voice rising sharply, "because I'm not leaving this place without you!"
"Growing…" the Doctor murmurs, his bleary eyes narrowing thoughtfully, "growing up..."
"What?" Donna asks hopefully, but he doesn't answer, because he'd thought that it had just been dumb luck that Donna hadn't been infected. He'd just assumed the creatures had mistaken her for dead when she'd been knocked unconscious, but what if there was more to it than that? What if they hadn't infected her, because they couldn't?
"Of course," he breathes and he could kick himself, because the answer has been right here staring him in the face the entire time.
"Of course what?" Donna asks. "You've thought of something," she says, "I can see it on your face."
"Maybe," the Doctor admits, "but it doesn't matter," he says shaking his head. He crawls back to the still glowing crystal, scooping it up with numb fingers.
"How can you say that?" Donna demands, hastily bundling herself back up against the bitter cold. "Of course it matters."
"It doesn't matter because it's too late Donna," he snaps, his patience wearing thinner the longer she argues with him. "I mean yes, maybe I could find a cure if I had a week and a team of geneticists working with me, but we haven't got anywhere near that sort of time," he says, slinking back towards her and dropping the crystal into her hand.
"So we leave now," Donna says, "we go back to the TARDIS and we find a place where they can help you."
"I can't leave," he insists.
"Why not?" Donna cries, clearly exasperated.
"Because it doesn't work that way!" he shouts back, his stomach cramping painfully. "I can't come back later, because I'm here now." He casts a wary glance at the fluttering clump of waning hybrids over their heads. "This base was inactive for over thirty years Donna," he says, "until I came along and brought the mainframe and environmental systems back online. A project like this would have gotten its start at the top. Even after all these years, it's possible this base is still being monitored by whoever sanctioned it. They may have already dispatched a ship to investigate. Don't you see, I can't leave as long as that possibility exists. I have to end it now, before someone comes along and inadvertently unleashes something devastating onto the universe." He groans, doubling over as burning pain radiates up from his abdomen, his back tensing with the intensity of it. "There's nowhere we could go that would be safe anyway," he says, gritting his teeth. "I'm not safe," he gasps, tiny beads of cold sweat springing out all over his bruised skin.
"What about Torchwood?" Donna asks, helplessly wrapping her arms around him. "They spent all those centuries studying you."
"So they could figure out how to kill me," the Doctor gasps.
"My point is they must know more about Time Lord physiology than anyone else," Donna says, pulling a face. "If anyone could help you, it would be them."
The Doctor frowns, though she's not wrong. It seems presumptuous to expect Martha and Jack's help after purposely avoiding them for so long.
"You were always going to have to face them sooner or later," Donna says, as if reading his thoughts.
He heaves a trembling sigh, his lips quirking sadly as he shakes his head. "There isn't time Donna," he says, "I need to get back to the research lab and overload the main computer. It's the only power source large enough to destroy the entire base."
"Don't computers just shut down if they overload?" Donna asks.
"Not if I override the safety protocols first," the Doctor grunts, blinking sweat from his bleary eyes, "the resulting arc flash should ignite the carbon particles suspended in the air and destroy the base." He licks his lips, swallowing bile as a wave of nausea passes through him. "It'll take some time for the feedback to build up," he says, somewhat breathlessly, "but not nearly enough to make it back to the TARDIS. I'm sorry Donna," he gasps, when she starts to protest, "but there's just no other way. Get back to the TARDIS and let her take you home."
"What if I bring her to you," Donna says suddenly. "You said it yourself, I'm getting pretty good at piloting her."
"Piloting maybe," the Doctor says flatly, "but you've never set coordinates before, and all the controls are in Gallifreyan.
"I'll muddle through," Donna says stubbornly. "At least let me try," she pleads, her blue-green eyes bright with unshed tears, "please…"
The Doctor caresses her cheek, his fingers numb and stiff with cold. HisDonna, so stubborn and opinionated and brilliant, like a force of nature. He has the overwhelming urge to tell her how much he loves her at this moment.
"All right," he says instead. He's only humouring her, but she doesn't need to know that. Once she's safe, the TARDIS will make sure she stays that way.
Donna throws her arms around his neck and clutches him to her as if her life depends on it, but the Doctor can't quite bring himself to return the hug.
"Take the crystal and get back to the TARDIS," he tells her.
"What about you?" she asks.
"I've got another torch," he says, his lips quirking fleetingly, "always carry a spare, that's my motto."
"Oh really," Donna says, "I thought it was run away really, really fast."
"That to," he says, "now go."
She crawls to the mouth of the chamber and quickly slips into the pitch black tunnel beyond it. She rises to her feet, clutching the warmly glowing crystal in her mitten clad hand like a beacon, closing her eyes for a moment to get her bearings.
"I've found her," she says after a moment, her eyes snapping open as if she can't quite believe it was that easy, "she's not far."
"Which way to the research lab?" the Doctor asks, his temporal and spatial senses winking in and out like flickering stars behind his eyelids.
Donna frowns. "How the hell am I supposed to… Oh," she says, blinking suddenly as the TARDIS presumably lays it out for her. "Wow. Better than GPS," she says, then points into the inky darkness over her shoulder. "Back that way about one hundred and fifty metres, then bare left for another fifty or so."
"Right," he says. He pulls a slim silver torch from his fleece lined pocket and follows Donna out into the tunnel. He swallows, slowly rising to his feet as Donna lingers beside him, her wool encased hand pressed flat against his heaving chest.
"Go," he gasps, giving her hand one final squeeze before they part.
"This isn't goodbye Spaceman," she says firmly, "just… just try not to do anything stupid before I get back," with that she turns and begins to make her way down the icy tunnel, the glowing light crystal bobbing in her hand as she carefully picks her way over the uneven ground.
"Been there, done that," the Doctor mutters crossly, before turning somewhat unsteadily and stumbling off in the opposite direction.
It takes longer than he'd anticipated to get back to the lab, his blurry vision hindered by murky shadows and his limbs stiff and aching with cold or with the virus, he can't really tell. By the time he reaches the slightly illuminated laboratory chamber, he's got the shakes so bad he can barely keep hold of the torch. Its roaming beam bounces around the room like a disco spotlight.
The motionless body of a hybrid glimmers beneath a jagged chunk of ice in the doorway. The Doctor frowns and steps over it, his knees going momentarily weak as more capillaries burst beneath his skin and he doubles over in pain, vomiting something that looks like used coffee grinds onto the frozen ground.
"Right, well that can't be good," he murmurs, dragging a trembling hand across his damp forehead.
He hears movement coming from behind him and anxiously spins around, the erratic torch beam playing over the edges of the empty doorframe. The Doctor scans the ground. The lifeless creature hasn't moved. It's still laying crushed beneath the sharp ice. His mind must be playing tricks on him.
He swallows and turns his attention to the sputtering computer console in the centre of the room. He drops to his knees in front of the access panel, grimacing in pain as he removes it with trembling fingers, trying to ignore the fact that his fingertips have gone all black and sticky as he trips the circuit breakers on the voltage suppressor clamps and removes them one by one from the flickering mainframe.
He drops the last one onto the frost covered ground and staggers to his feet, his aching fingers moving stiffly across the keyboard as he writes a simple self-replicating virus program designed to eat up memory and overload the computer's central core processor with vast amounts of useless information.
He frowns, squinting at the flickering monitor above his head as the last bits of code scroll across the screen when a chitinous black hand seizes him by the shoulder, its long sharp claws digging painfully into his tender flesh. The Doctor gasps, bruising painfully in the creature's iron grip. He struggles to tap the return key on the keyboard, trying to execute the virus even as the creature drags him away and flings him across the room.
He lands in a crumpled heap against a moulded steel table leg, the impact knocking the wind out of him as the whining hybrid slowly advances on him, its movements somewhat erratic in the oxygen starved atmosphere. It knows what he's trying to do, or rather the retro-virus does and has jump started a soldier drone to deal with the threat.
The Doctor grits his teeth and climbs to his feet, his own oxygen reserves nearly depleted. He quickly scans the lab table behind him for a defensive weapon of some kind. Everything on it is bolted down; and he lost the sonic when he lost his anorak.
He grimaces, slowly backing away and placing the permafrost coated table between himself and the erratically advancing creature. It hisses and flings itself at the table, landing on top of it to loom threateningly over the Doctor as he cowers against the tunnel wall. It lunges at him and the Doctor drops to his knees, rolling under the table and scrambling to his feet again as the thing bounces off the tunnel wall behind him.
Arm outstretched, the Doctor stabs the keyboard and instantly the monitor above his head begins to fill with line after line of endless scrolling data. The quivering hybrid screams, its formidable mandibles gnashing as the Doctor squares his shoulders and turns to face it.
"Yeah, I know," he says, the sputtering mainframe at his back already beginning to whine and spark with mounting feedback, "but you know what they say. Some days you're the windscreen. Some days you're the bug."
The thing unfurls itself, the chitinous carapace covering its back splitting into rudimentary wings. The Doctor closes his eyes, resigned to his fate. The TARDIS should have gotten Donna to safety by now and that's all he cares about really, though he does regret not kissing her when they didn't say goodbye back in the tunnel. He has other regrets too of course. Not living to see the birth of his son, or knowing his name. Ironic that, a Time Lord not knowing his own son's name, but mostly he regrets that one last kiss that he and Donna never shared.
The creature slams into him and the Doctor goes down hard, the cold hard ground rushing up to meet his burning back and knocking the wind out of him. Dripping mandibles hover inches from his face and the Doctor smiles, giddy from lack of oxygen. The mounting feedback overloading the computer's central processor mingles with the creature's enraged bush-cricket whine, reaching an oddly familiar crescendo as it goes in for the kill, its gnashing jaw headed straight for the Doctor's vulnerable throat.
He closes his eyes, bracing himself for the blow that somehow never comes. Instead, the creature rears back, its entire body convulsing for a moment before it falls to the ground in a stunned heap. A very determined looking Donna is stood over it holding the console room mallet in her hand. The creature collects itself, rising to meet the new threat and Donna swings the mallet in a wide arc like a cricket bat, delivering a wicked uppercut to the thing's face and crushing one of its protruding mandibles. It goes down in a twitching heap and Donna drops the mallet.
"Doctor!" she cries, her coarse wool mittens chafing his tender skin as she tugs at the sleeves of his pullover. "Doctor get up!"
The Doctor blinks, his vision disintegrating around the edges as he tries to focus on her face. Mounting feedback fills his aching head like a buzzing hornet's nest and he seems to have lost all control of his aching limbs.
"Doctor please!" Donna pleads, and he forces himself to move because she'll be caught in the blast if he doesn't.
She helps him to his feet, his knees instantly buckling. He goes down onto his hands and knees. The TARDIS, briefly flashes at the edge of his vision as his head swims. Donna falls to her knees beside him, urging him to keep moving, desperately tugging at his grubby clothes. The whining feedback reaches a critical pitch and the Doctor grits his teeth, struggling to his feet again. The stunned hybrid shakes off the effects of Donna's attack and staggers after them as they stumble towards the open TARDIS doors, the console room shining with an inviting amber glow and the promise of blessed oxygen.
They stumble over the threshold, the enraged hybrid snatching at the Doctor's collar with its viscous claws before the TARDIS doors fly shut with a resounding creak, locking the creature out. The creature rakes the blue wood and shrieks like an old time cinema monster. The Doctor stumbles onto his hands and knees, taking in great gulps of oxygen-rich air as Donna flies up the catwalk towards the console.
Suddenly a bright flash of light radiates through the door seams and the hybrid's buzzing shrieks abruptly cease in the wall rattling explosion that follows a few seconds later. Donna screams, falling to the floor as the TARDIS tumbles, caught in the shockwave. The Doctor struggles to his feet and stumbles up the catwalk. The TARDIS reels through the air as he grips the console, throwing levers and spinning dials until she slips into the vortex and her flight path levels out. He sets the coordinates for Cardiff 2010, then sinks to the floor, gasping for breath as he finally gives in to the pain, his entire body trembling with the intensity of it. Donna crawls over to him, wrapping her arms around him and hoping that the disorientated TARDIS is taking them where they need to go.