The planet stinks; literally. It smells like a giant bog, which is fitting Donna supposes since it apparently is one. They emerge from the TARDIS into perpetual twilight and she immediately claps a hand over her nose and mouth, overcome by the intense sulphur reek of the place.

"I think I'm going to be sick," she says, gripping the Doctor's coat sleeve, and it's true. Her stomach flips and she's suddenly doubled up and dry-heaving over the decaying vegetation.

"Hang on, hang on, hang on," the Doctor calls, fumbling frantically inside his pockets for a moment. He emerges with a small vial of clear liquid, which he quickly uncaps and upends between his thumb and forefinger. He stoops down beside Donna and dabs the liquid all around her nose and nostrils.

Just like that the stench disappears, replaced by a crisp freshness and the subtle hint of roses. Donna breathes deeply and swallows a few times to make sure she's regained control of her protesting stomach, her hand resting on his shoulder for support.

The Doctor eyes her with some concern, tenderly tucking an errant ginger ringlet behind her ear. "Better?" he asks with a hopeful smile. Donna nods and together they slowly stand up.

He replaces the cap on the vial and returns it to his coat, somehow managing to keep a steadying hand on Donna's arm the entire time.

"What was that?" Donna asks, indicating his pocket with a tilt of her chin.

"Oh just a bit of olfactory flimflam," the Doctor says gently.

"How long does it last?" Donna asks, tentatively touching the tip of her nose. Her skin feels completely dry. No tackiness or residue of any kind, yet the congealing clouds of sulphur mist hanging in the air may as well be candy floss for all she can smell of them.

"Several hours at least," he says. "We should be long gone from this place by the time it wears off."

"Aren't you bothered by the smell?"

He shrugs. "Respiratory bypass," he says simply, as if that explains everything. "Right then," he says, taking her hand, "ready to go on now?"

Donna smiles and nods. "Yeah," she says with far more conviction than she feels.

The Doctor squeezes her hand and begins to slowly lead the way through the oozing swamp, picking out the driest path he can find between the swirling pools of oily black water.

"Watch your step," he says with a grimace, "I don't like the looks of that water."

Donna can't help but agree. She eyes the dark pools suspiciously, expecting at any moment to catch a glimpse of decaying bodies bobbing to the surface as they skirt past.

She suppresses a shudder at the thought. "How far is it?" she asks, trying to turn her mind to something else.

The Doctor reaches into his pocket and pulls out something resembling a TV remote with blinking lights in a variety of patterns and colours playing across its surface. He squints at it for a moment and Donna smiles, because despite his claims to the contrary she knows he's a bit far-sighted and needs his glasses to see it properly.

"About five kilometres that-a-way," he says with a vaguely eastward tilt of the head.

Donna frowns up at the slate grey sky and the pair of twin suns hovering just above the horizon; tiny greenish blips of anaemic light that barely brighten the planet beyond permanent dusk. The air is cool and clammy, but warmer than she'd expected due to the greenhouse gasses choking the planet's atmosphere.

"Why can't we ever intercept a distress signal from Bermuda?" she grumbles as they continue to plod along.

"What's so distressing about Bermuda?" the Doctor asks absently, checking the readings on the remote device again with his glasses on this time.

"My point exactly."

The Doctor smiles, eyeing Donna over the rims of his glasses. "We didn't have to come you know," he says softly, "we could have left it alone; ignored the signal."

"No, we couldn't" Donna says simply.

"No," the Doctor agrees, "we couldn't."

They continue to pick their way through the steaming bog. The going is slow and tedious due to the soft earth literally swaying beneath their feet. The further they travel into the swamp the more Donna's anxiety grows. She knows it's just her imagination, but she can't quite shake the feeling that there are eyes upon them, silently marking their progress.

Even the Doctor is uncharacteristically quiet. He's suddenly grown very pale Donna notes, his lips drawn into a grim line.

"It's a bit like the movies this," she says, intending to ease the tension, but startling herself with the loudness of her own voice instead.

"Hmmm?" the Doctor mutters.

"It's so quiet."

"This planet is dying."

"No but I mean not a bird, or an insect, or even a blowing leaf, no sound at all. It's eerie." She grins suddenly. "It's always what happens in the movies just before the zombies attack."

She expects a chuckle from him at least, but is surprised when all she gets is a slight grimace. "I don't know about zombies," he says quietly "but there's definitely something here."

Icy fingers grip Donna's spine as she again finds herself fighting off a slight case of nausea. "The ones who sent the distress signal you mean," she says without much conviction.

"No," the Doctor says, confirming her fears. "Not them. Something else, some sort of presence."

"What, like a ghost?"

"More like a primitive intelligence," he says. His eyes slide shut and his fingers brush his temples. "I can feel it," he says thickly, "buzzing around inside my head like a swarm of angry bees." He opens one eye and glances at her. "It's really annoying," he says wryly, before screwing his eyes shut again with a slight groan, "also, quite painful actually,"

Donna takes a step towards him in growing concern, her hand brushing his arm. "It's not harming you is it?" she asks anxiously, because distress signal or no, she's not about to let some alien what's-it harm him.

"No. I'll be fine," the Doctor says, "I just need to..." his voice trails off and he goes suddenly very still.

"Doctor?" Donna cries.

He's just stood there, completely motionless like a lanky statue. Donna doesn't even think he's breathing.

"Doctor!" she cries again more insistently this time.

She anxiously chews her bottom lip as panic begins to settle in, wondering if he's slipped into some sort of coma. She suddenly feels very alone and very vulnerable without him.

"Doc-"

With a sharp inhalation of breath the Doctor's eyes abruptly snap open and Donna takes a startled step backward, nearly stumbling into an inky black pool of alien water in the process.

"Much better," he says, grinning like a cat. Donna scowls at him and punches him soundly in the fleshy part of his shoulder.

"Oi!" he cries indignantly, clutching his arm, "what was that for?"

"For scaring the hell out of me that's what!" Donna shouts at him. "You don't do that. You don't just go 'gosh I'm in pain' then fade away like that. I thought you'd got brain damage or something you bloody idiot!" she cries, swatting his arm a second time.

The Doctor just stands there, clutching his arm and looking sheepish while Donna seethes and fights back the tears threatening to blur her vision at any moment.

"I'm sorry Donna," he says at last, "I didn't mean to frighten you."

"Yeah, well you did," she says hotly, but the relief in her voice is already evident.

The Doctor smiles. "I really am sorry," he says again.

Donna's eyes roll skyward, "I know," she says indulgently and the Doctor's smile turns into a grin.

"What were you doing anyway?" she asks.

"Building a bigger moat," he says rather cryptically.

"You what?"

"It's not important," he says simply, "probably best to keep moving though."

…...

Eventually the soggy ground gives way to more solid footing and a huge black lake that stretches all the way to the horizon. The water is completely still; a shining black pearl of mirror like smoothness. Nothing disturbs the surface, not a drop or a ripple.

Donna imagines what it would feel like to skate across it, to feel the cool glass beneath her feet.

"Donna?" the Doctor calls warily, "what are you doing?"

Donna turns to find that she has somehow broken away from him. She looks down at the shining water sucking hungrily at the shore and finds herself taking a step towards it. There's no conscious thought behind the action, she simply feels compelled to do it, as if her feet have taken on a life of their own.

"Donna, don't!" the Doctor cries. He runs towards her, his arm poised to pull her back from the brink, when he suddenly stumbles. A ragged scream tears from his throat and he falls to his knees, clutching his head as if in intense pain.

The water is like ice, instantly numbing Donna's legs up to the knees. She plods forward, ignoring the Doctor's strangled pleas to stop. The tiniest corner of her mind that is still under Donna's control makes her glance back at the shore.

He's fallen to his hands and knees, gritting his teeth. There are tears streaming from his eyes, as if the very act of seeing has become painful to him. He's half commanding, half begging her to stop, but Donna's actions are not her own. Her compulsion to keep moving forward is almost painful in its intensity.

She watches him collapse face first into the soft earth, completely disconnected from the event save for that one tiny corner of her mind railing impotently inside her head.

She turns away, continuing towards the thick black tentacles now looming over her head. They are somehow in the water and of the water at the same time and Donna wades closer, the water now up to her waist.

For a moment she just stands there, transfixed by the rainbow patterns of oil dancing majestically along the surface of the dripping tentacles. Then with the speed of a whip, they suddenly grab her around the waist and chest, pinning her arms to her sides and dragging her below the water's surface.

Fifteen-seconds later, the Doctor's eyes snap open and he springs to his feet, discarding his coat on the sand and diving like a bullet into the inky black depths behind her.

…...

The water is like a million shards of ice breaking across the surface of Donna's skin. It robs her of what little breath she'd saved before being dragged under. The fact that the grey veil has lifted from her mind returning her to herself, is of little consequence as she is dragged deeper and deeper into the oily black pool towards the gaping maw below.

Her chest is on fire, the icy water squeezing her ribs and lungs as if she were caught between two grinding boulders. The effort to hold her breath is rapidly becoming too great, her vision already beginning to crumble around the edges as oblivion looms.

Then she sees it. A small blue light cutting through the blackness above her. At first, she thinks she's imagining it, but then she sees the Doctor darting towards her, illuminated in the back-glow of the sonic screwdriver. He swims the way he runs; fast. He slices through the water like an Olympic swimmer, his long legs kicking mightily behind him.

Donna struggles feebly in the creature's grip as the Doctor aims the sonic at the tentacles binding her. She feels a rippling shudder run through them before their grip on her goes suddenly slack. He grabs her by the shoulders and pulls her free, immediately propelling them back towards the surface with a powerful kick of his legs.

Donna grips his shoulder, her eyes wide open in panic. She can feel herself teetering on the very edge of consciousness. The Doctor takes her face in his hands and covers her mouth with his, filling her lungs with the breath from his own.

Then he suddenly disappears in a cloud of bubbles, yanked away by a thick tentacle wrapped around his waist. The sudden jolt knocks the sonic from his hand and Donna watches in horror as it spirals impotently into the darkness.

Without a second thought, she takes off after it, though she can already feel his borrowed breath beginning to wane in her lungs and the icy water is turning her body stiff and clumsy.

She catches sight of the Doctor, gesturing madly at her. His intent is clear, he wants her to leave him behind and make for the surface, but she'd never leave him, not ever, not in a million years.

Her path is dimly illuminated by the creature's bioluminescence. For the first time, she gets a good look at the thing. It's huge, nearly as big as the bottom of the lake; a writhing mass of oily tentacles and a huge maw of a mouth lined with row after row of jagged teeth. It's like some sort of giant carnivorous plant, and it's drawing the Doctor into itself like a fly into a trap.

Desperately, Donna slices through the water after the sonic, dodging tentacles and fighting her own burning lungs. She's lost sight of it, but she's sure it's around here somewhere. She treads water for a moment, trying to get her bearings, her flame coloured hair spreading out like a halo at the very edges of her vision. Then she sees it, tumbling majestically end over end just below her.

She dives towards it, glancing anxiously at the Doctor still struggling valiantly in the sea monster's grip, unable to get to his tentacle encased pockets. How long can Time Lords hold their breath, she wonders. Probably longer than a human being can on average, but he's already used up most of his on her.

Her breath nearly spent, Donna makes a desperate grab for the sonic, only to have it tumble uselessly from her numb fingers. She grits her teeth and kicks with all her might, making a second grab. This time she manages to hold onto it, wrapping her icy fingers around it protectively. A tentacle ensnares her across the shoulder and Donna cries out in a wasted stream of bubbles as she's suddenly jolted downward, barely managing to keep hold of the sonic in the process.

Her entire body is beginning to tremble with the effort of staying conscious, but she manages to kick her way closer to the Doctor, holding the sonic out like a beacon before her. Through the tunnel that has become her vision, she focuses on the tentacle around his waist and presses the button.

The Doctor wriggles from the creature's grasp like an eel and darts towards her, the look of horror on his face telling her that he has no breath left to give her. She clings to the sonic, holding it out for him to take. He grabs her hand and she manages to push it into his just before her vision crumbles completely and everything goes black.

…...

Donna awakes on the soggy banks of the lake, wrapped up inside the Doctor's coat. The Doctor is hunched beside her, dripping wet and somewhat out of breath.

"Welcome back," he says softly, squeezing her hand and smiling a very relieved smile.

His hand is like ice and Donna's eyes stray to the torn sleeve of his suit jacket stained crimson with blood.

"You're hurt!" she cries, struggling to sit up.

"What, this?" he says dismissively, "It's just a flesh wound." He grins suddenly, "always wanted to say that," he says.

Donna rolls her eyes and flings her arms around his neck in a giant hug. The Doctor holds her close, his chin resting on the top of her head. He's trembling, Donna notices.

"You okay?" she asks, holding him a bit more tightly.

"Yeah," he says softly, "just don't scare me like that again."

"Promise," she says, resting her head on his shoulder. That's when she notices the giant ants.

There are three of them, sat in a very neat little row over the Doctor's left shoulder.

"Uh, Doctor," she says somewhat hesitantly.

"What?" The Doctor asks, following her gaze. "Oh right," he says. "Donna Noble, allow me to introduce Aqueduct Subsection B Worker Drones 111, 445 and 9, or 909, or possibly the 1 after 909, I'm not really sure" he says with a shrug.

Donna flashes them a shy smile. "Hello," she says with what she hopes is a friendly nod.

The three ant-men wave jovially to her with their antenna and clack a funny sort of greeting with their little mandible mouths. Their accent is strange, like sticks beating together, but she could almost swear they're saying something like, "All right Miss."

"They're Trilaxians," the Doctor explains, "not real big on names Trilaxians. Brilliant engineers though. They invented a nearly indestructible metal that's used throughout the known galaxies in ship building. Anyway, I've been calling them Jeff, Steven and Bob to eliminate all that, 'Aqueduct Subsection B' nonsense. The one on the end is Bob. I think he looks like a Bob. Don't you think he looks like a Bob Donna?"

Donna turns a dubious eye on the little creatures, but they all look exactly the same to her.

"They're the ones who sent the distress signal," the Doctor continues a bit more soberly.

"Because of that thing out there?" Donna asks.

"The Mygalomora yeah," the Doctor agrees with a nod.

"The what?"

"Mygalomora. It's an extinct species, or it ought to be anyway. Do you know why?"

Donna shakes her head.

"It's because they'll eat anything," the Doctor says grimly, "they devoured everything on their home world, and after every last creature was gone, they started in on each other. Until finally there was just one left, that one apparently," he says with a curt nod towards the lake.

"It really is just a mindless monster," Donna says with a shudder.

"No, it's worse than that," the Doctor says, his eyes sparking angrily, "it's an evolutionary dead end."

"How'd it even get here?" Donna asks, confused.

"It hitched a ride on the meteor that destroyed this world," the Doctor says. "It passed so close to the planet that it knocked it out of geosynchronous orbit with the suns and ripped away part of the atmosphere. This planet really is dying you know," the Doctor says pulling up a clump of mouldy sod, "it's rotting from the inside out, like a bad egg."

Donna's nose wrinkles in distaste.

"First it destroyed the planet," one of the little ant-men says sadly, Donna thinks it may be Jeff, "then it destroyed us."

"There used to be over a thousand Trilaxian colonists on this world," the Doctor says flatly, "these three are all that's left. Three out of a thousand."

Donna feels suddenly nauseous again. "I'm so sorry," she says, her heart going out to the poor little insectoid creatures.

"Unfortunately the Trilaxians proved especially vulnerable to the Mygalomora's kind of mind-control," the Doctor continues. "It lured them here the same way that it lured you into the water Donna."

"I don't get it though," Donna says thoughtfully, "why not just control me in the water as well? Make an easy meal of it."

"I don't think it could," the Doctor says. "It wasn't native to this planet remember? It adapted to the water, but not completely. Some element in it must have blocked its power."

"It couldn't control you at all though," Donna says softly, remembering his earlier ordeal.

"No," the Doctor says with a slight frown. "Once it figured that out, it just settled for attacking me instead."

Donna gives his hand a sympathetic squeeze.

"There's more Donna," the Doctor says, suddenly very serious indeed.

"Tell me," she says.

"There's a reason these three were spared," he says indicating the three Trilaxians with a nod. "The Mygalomora was compelling them to build a ship."

The implications hit her at once. With a spaceship at its disposal and a crew of enslaved minds to fly it, there would have been no limit to the worlds that thing might have visited and left devastated in its wake.

"I couldn't allow that to happen," the Doctor says softly, "not when by all rights, it should have been dead long ago."

"Course' you couldn't," she says, her eyes straying to his bloody sleeve, "so it's been?"

"Sorted," he says flatly. He still wishes there had been another way though, she can tell that just by looking at his face.

"I'm sorry."

He shrugs, but breaks into a smile after a moment.

"Ready to go?" he asks.

"Yeah," Donna says with a nod.

"Just have to drop this lot at the nearest space station," he says, "and after that?"

Donna breaks into a wry smile. "I hear Bermuda's nice this time of year," she says.

~END~