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Ephyra-5
The hangar was quiet beneath softly humming sodium lamps, the walls the colour of old bone. Rows of trucks stood in precise formation, all sealed, all waiting.
Dr. Lheina Sorell’s footsteps echoed through the silence, far too loud for someone who wasn’t supposed to be here. She only needed her glasses—left behind after the last round of sample cataloguing—and then she’d go home.
One truck near the centre wasn’t fully processed yet. She made a beeline for it. A rectangular tag hung from the latch, matte black with stark white lettering. It might as well have been a bar code to her without her glasses.
She leaned closer, squinting through blur. Inside, something caught the light. That familiar, faint glint of metal frames.
“There you are,” she muttered, and snapped the latch open.
A siren howled before the black tag hit the floor. Red light strobed through the hangar, and alarms clawed at her ears. Lheina raised her hands instinctively as armed soldiers burst through the doors.
“I didn’t know!” she shouted. “I couldn’t read the…”
“Seal breach detected,” someone barked into a comm. “Myrdaceps containment compromised. Initiate lockdown!”
The commander’s visor turned toward her, catching the crimson flash. “Name.”
“Dr. Lheina Sorell! Terraforming division!”
That changed everything.
“Don’t shoot,” he snapped to his team. “We need her.”
Steam hissed from vents overhead. Somewhere deeper in the hangar, a pressure valve screamed and died. “Secondary locks aren’t responding,” someone shouted. “It’s already in the air.”
Sure enough - she could taste it. The air was wrong, metallic, and way too warm.
A soldier thrust a rugged laptop at her. The startup screen bloomed into a white spiral inside a stylised black mushroom cap.
“You wrote the terraforming reports,” the commander said, breath tight with urgency. “We need everything on Myrdaceps nutrient dispersal. Now.”
“I don’t remember it all by heart! I need the primaries…”
“Then get them!”
She sat. Forced herself to focus. Her heart hammered in her throat. The air thickened with every breath - syrupy, damp – and a faint sweetness clung to the back of her tongue.
“I can retrieve some general distribution reports,” she muttered. “But for the actual nutrient dispersal, I need to log into my account…”
“You’ve got two and a half minutes,” said the commander. “Then we go. Otherwise, it finds us.” He tapped the face of his wrist-chrono. A digital timer began to tick down: 02:30… 02:29… 02:28…
Lheina typed as fast as she could, her eyes watering from the screen’s glare and the thick air. The machine hummed, a frequency just below hearing, almost soothing—until it wasn’t. The hum deepened into a pulse. She shivered.
The soldier beside her tapped the table. “Um - your laptop is overheating.”
The casing trembled. Thin lines of red light traced across the surface, like veins beneath skin.
Lheina leaned closer. “What…”
A seam along the keyboard split, and something slid out – pale red threads, hair-thin, impossibly alive. They twined around the soldier’s wrist. He jerked back with a surprised shout. The threads tightened, burrowing into his sleeve, into flesh.
“Cut them!” the commander roared, but no one moved.
The laptop’s screen filled with fractal red growths, petals blooming, dividing, spiralling infinitely.
The soldier went still. His breathing evened out. Then he turned, broadly. His voice came doubled, wet and dry together: “Stay. Warm. Join.”
The commander fired once.
There was a flash. Smoke. Silence.
No one dared to breathe.
When it cleared, the soldier was still standing. His chest smoked; filaments pulsed through the wound, knitting it closed from within.
Lheina scrambled backward.
Then she ran.
She bolted down service corridors that bled emergency red, through air that shimmered with spores. Every breath scraped. Each footstep echoed behind her.
She reached the lower maintenance levels. Yellow paint peeled from walls marked CAUTION: HOT. The heat pressed against her palm as she knocked the doors open. She stumbled into a washroom, slammed the door, twisted the lock.
Her pulse hammered so loudly she thought it would call them – it – to her. She slid down the tiled wall. Sweat ran down her spine. Her whole body shook with the effort of staying quiet.
She froze as she heard a sniff outside the door, followed by a low growl.
The metal door began to bow inward with a slow groan. A thin, grey, wrongly jointed claw pushed through the seam between door and frame. Another followed. Then another.
The lock shrieked.
Lheina crawled backward to the far corner, pressing herself against the cold tile. “Next time,” she thought wildly, “Sit higher. On the toilet lid. Hide better.”
She didn’t know why next time mattered.
The door started to crack. Warm, spore-laden air rushed in, stinking of soil and blood. Something big shifted right outside. Through the widening crack she saw it: limbs slick with filaments, red eyes glinting like wet opal.
The crack opened wider.
And wider…
Until the door splintered open.
Far above Ephyra-5, the TARDIS tore out of the vortex with a sound like a thunderclap caught in glass.
Inside, the lights flickered wildly. The Doctor clung to the railing, and Donna Noble had both arms wrapped around the console as the floor lurched.
“What was that?” she shouted.
“Felt like a heartbeat in the time vortex,” he shouted back, half-grinning. “Never a good sign. Or maybe a brilliant one.”
Donna pointed at the monitor. Beneath them, a planet shimmered under a velvet red haze, its surface veined with slow-moving light. “Tell me we’re not landing there. That’s not…”
The TARDIS shook again.
“….Sensible!”
“Oh, Donna,” he sighed, eyes bright. “When have I ever landed somewhere sensible?”
He threw the final lever.
The time rotor roared like a living thing, and the blue box plunged toward the clouds.
The TARDIS landed a bit crooked, half-sunken in moss the colour of dried blood.
When the doors opened, a soft hush poured in. Outside, red spores drifted through shafts of milky light. Enormous fungal trunks arched above them, their caps glowing faintly orange, like lanterns hung in fog. The air smelled of wet stone and overripe fruit.
The Doctor stepped out first, squinting at his readings. “Atmosphere breathable. Temperature... pleasant enough. Oh, but look at this place! It’s gorgeous!”
Donna followed, hand over her nose. “It smells like a compost heap.”
“Terraforming world in an early stage, by the smell of it.” He crouched, brushing a luminous petal. “Bio-luminescent mycelia… Ooh, someone’s been busy.”
“Busy is one word. Let things get mouldy is another one.” Her voice echoed oddly, as if the forest itself repeated her ...go mouldy...
They both froze.
The Doctor glanced around. “Acoustic reflection? Hm. Interesting.”
They moved cautiously between the towering stems. Filaments hung from the caps like silk curtains, brushing against their shoulders, leaving faint glittering residue on skin and fabric. Every motion seemed muffled, and the air felt heavy with humidity.
Donna spotted movement ahead, just a shimmer.
She slapped the Doctor’s arm, “Did you see that?”
“Probably just a tree branch. Or a garden gnome. Or both.” He grinned.
As they walked on, a few mobile shelters emerged. They were light, portable polymer domes, more roof than wall, their panels veined with red fungus. Thin power cables trailed from one to another like umbilical cords, vanishing half into the crimson moss.
The Doctor touched the nearest door seal, jaw tight. “Field-labs. Quick deployment build. Someone planned to stay just long enough to be clever.”
Donna stared at the veined panels. “Yeah. And didn’t leave.”
He smiled at her. “Only one way to check.”
“Oh no. No, you are not just strolling into that mushroom igloo like it’s a Tesco.” She gestured sharply at the fungal webbing. “That screams infection. That screams don’t touch.”
“Donna,” he said gently, “if something went wrong here, this is where it would tell us how bad.”
She glared at him for a beat. Then she sighed, furious and loyal in equal measure. “Fine. But if anything jumps at me...”
He gave her sleeve a reassuring squeeze and stepped inside.
The air was stale and cold. Console lights flickered through a web of mycelium. Each display glowed with the same black-and-white logo: a spiral nested inside a stylised mushroom cap.
“Let’s see what’s left of their systems,” he muttered, already sonicking the login. The machine gave a sulky little beep and yielded.
Static hissed. Then a recorded voice cut through, broken and breathless:
all personnel advised—containment breach—nutrient bloom accelerating— do not—open—
The message dissolved into static, then into a long, uncomfortable nothing.
Donna’s shoulders hunched. “I hate when recordings stop like that. That’s not an ending. That’s a cliffhanger.”
The Doctor didn’t answer immediately. The blue light flickered across his face as he scrolled. His expression tightened.
Donna leaned closer, voice quieter now. “Whatever they wrote in there… it’s the last thing they ever told anyone, isn’t it?”
The smell of iron and earth and something sweet hung in the air. He swallowed once. “Yeah,” he said softly. “I think it was.”
He scrolled into the next directory.
The ghost-blue light from the screen flickered across his face. Lines of data spilled down the screen: vitals, timestamps, names. Every data-entry line ended the same way, heart rate: flatline. Followed by a second column that said, activity: ongoing.
Donna’s throat tightened. “Flatline but still moving. How is that even…”
A sound drifted through the cracked doorway—thin, wavering, but clear: “… come… stay…”
Donna went still. “No. Nope. Absolutely not. Tell me that’s the wind.”
The Doctor didn’t answer. He turned slowly toward the opening, every line of him gone tense.
Outside, something moved between the trees. A grey shape threaded with faint red light, half-lost in shadow and bioluminescent glow. The air pressure seemed to change. A gentle, wrong breeze rolled inside the pod, damp and cool against Donna’s skin.
“Doctor,” she whispered, clutching his sleeve. “I don’t like this.”
Another sound drifted in. Not quite wind. Not quite voice. “Water…”
A single spore drifted lazily through the doorway and settled on the Doctors coat like a tiny, glowing red ember. He brushed it away with a forced laugh. “Oh, come on, it’s one speck of dust. Can’t let every microbe ruin a perfectly good mystery.”
Donna stared at him. “You’re impossible. We’re leaving. Now. Before whatever is outside finds us.”
He hesitated half a heartbeat, then nodded.
They backed away from the entrance and slipped out of the pod in the opposite direction.
Behind them, that voice followed like a breath at their backs.
“Stay…”
The air outside had grown thick, heavy with red motes that glowed when disturbed. The motes drifted lazily at first, then caught on movement, stretching into thin, trembling filaments that clung and resisted before breaking apart.
Every few steps, Donna brushed at her sleeves. “It’s like walking through cobwebs made of pollen dandruff,” she muttered. “It’s wrong.”
The Doctor’s mouth twitched, but his eyes never stopped moving. He swept the sonic through the air, frowning at the readout.
“Air density spiking. Spore concentration off the charts. Either this planet’s overdoing spring, or it’s come down with the universe’s worst infection.”
The forest ahead shifted.
Between the trunks, shapes resolved out of the haze. Tall. Slow. Human, at first glance. But they didn’t move like people. Their steps were measured, deliberate. Too careful. They stood in loose clusters with their heads bowed, as if waiting for something to tell them when to lift them again.
Donna’s voice dropped, the humour draining away. “Doctor… tell me that’s not zom…”
He lifted a hand, sharp and quiet. “Shh.”
He took a step forward.
“Let’s go see.”
Donna shot him a look that said absolutely not, then followed anyway.
They trailed one figure up a moss-covered rise. The ground gave underfoot, soft and wet, releasing a sour, loamy smell with every step. The thing ahead moved with a dragging rhythm, one foot heavy, one light, until it stopped beneath a mushroom cap the size of a house.
It stood there.
Just stood.
Its head lolled to one side. One arm hung loose, fingers twitching faintly, as if waiting for instructions that never came. Spores drifted down around it in a slow, steady fall, like ash.
Donna let out a thin, brittle laugh. “Oh come on. That’s a zombie. Really, Doctor? You bring me all across the universe to see zombies?”
“Not on purpose,” he said quietly. He squinted, eyes narrowing. “But look at it. The physiology’s wrong. No breath. No body heat.” He swallowed. “That thing’s dead, Donna. But it’s still alive too.”
“Yeah,” she said flatly. “Like I said. Zombie.”
He shot her a look.
“What? You just said dead and alive. That’s the job description.”
She stared harder at the thing, dread creeping in around the edges of disbelief. “His skin… Doctor, that’s mould. He’s growing mould!?”
Her voice echoed more than it should have.
The figure snapped its head toward them in a jerky motion that made Donna flinch.
The Doctor’s voice cut through the moment, all warmth gone. “Donna. Behind me. Now.”
The thing’s face split down both cheeks like baked clay. Its mouth opened too wide, wider than bone should allow. When it spoke, the words came out perfectly shaped.
“Come. Stay. Be warm.”
The sound carried with it a breath. A cloud of crimson spores burst from its throat, rolling toward them.
The Doctor raised the sonic. “Stay back!”
The figure cocked its head, listening. When it spoke again, its voice was soft. Tender. “We are joined. You are not. Come.”
Movement rippled through the trees.
More shapes emerged. Men. Women. A child in a torn pressure suit. Animals. All of them swaying in the same slow rhythm, whispering together. The forest itself seemed to inhale.
Donna’s fingers dug into the Doctor’s sleeve. “We’re surrounded.”
“Run,” he said.
No grin. No banter. Just the word, flat and sharp.
Roots slick with dew snagged at their shoes as they ran. Behind them, the whispers followed, thinning and stretching, no longer words so much as breath pulled too long through a mouth that did not need air.
They burst into another clearing. Smaller. Closed-in. The trunks around it pulsed faintly with bioluminescence, a slow, patient glow.
Donna bent double, coughing.
The Doctor turned to look back.
Something stepped out of the dark.
Something that had been human once. That much was still visible in the shape of it, in the way it stood. Now its skin was grey and dull, threaded through with veins of red light. Half its face had collapsed inward, replaced by a lattice of fungal growth that glistened wetly.
Its hand shot forward suddenly, joints flexing in a way that was almost serpentine, fingers twitching and correcting mid-motion as if guided by something that knew exactly where it was going.
Before the Doctor could react, the hand clamped over his face. Five long fingers spread wide, sealing off his mouth and eyes. Only his nose was left uncovered.
He jerked once, every instinct screaming to tear free.
Then he froze.
Breathe. Just breathe, he thought.
“Doctor!” Donna lunged toward him.
“No - don’t!” His voice came muffled beneath the grip. “Stay back. Donna, don’t touch me.”
Every breath through his nose filled him with cloying sweetness. Heat bled through his skull, slow and intimate. A prickling sensation spread beneath his skin, as though countless fine threads were brushing along his nerves, tasting, listening.
It was not hurting him.
This was worse. He could feel it tracking his pulse. Tracking every fibre of him.
He snapped the sonic up and pressed it hard against the creature’s wrist.
The blue pulse cracked through the clearing. There was a sharp hiss. The stink of scorched earth.
The host convulsed and released him. It staggered back, its body unravelling as it moved, collapsing into drifting red filaments that dissolved into the air.
The Doctor stumbled, dragging air into lungs that suddenly felt far too small.
Donna caught him, hands gripping his arms. “Oh God. Doctor. Are you okay?”
“Fine,” he said, far too quickly. His voice was hoarse. His pupils were blown wide, sweat beading at his hairline. “Minor contact. No penetration. Probably.”
“Probably?” she snapped.
He managed a crooked smile that didn’t settle anywhere properly. “Well. It’s me. I like to stay optimistic.”
From the trees, another sound drifted closer. Not a voice. Not quite. Just breath, layered and patient. “Come.”
The Doctor flinched, then straightened up, forcing brightness back into his tone like armour pulled on too fast. “Right. Back to the TARDIS. Lovely planet. Appalling manners.”
He set off at a brisk walk, one hand pressed briefly to his temple when he thought Donna wasn’t looking.
At his collar, a faint spore stain pulsed twice.
And again.
Perfectly in time with his hearts.
The TARDIS doors slammed behind them, sealing out the whispering forest. For a moment, the silence inside felt like rescue.
Safety.
Then came a slow, deep pulse, felt more than heard.
The Doctor straightened, eyes snapping to the console.
“That wasn’t me. That…” He glanced at Donna. “Did you touch something?”
Donna folded her arms. “Why are you looking at me? Statistically speaking, you break more things around here than me.”
He paused. “Fair point.”
The console flickered then steadied again, but the hum of the ship had changed ever so slightly. The Doctor frowned and tugged off his coat. The fabric hit the floor with a damp slap. He wiped at his neck, then his forehead, frowning at the sweat on his fingers.
“Bit warm in here, isn’t it?”
Donna stared at him. “You’re sweating. And you’re pale. That’s a terrible combo. My friend Vicky once had heatstroke…”
“I’m fine,” he said quickly. Probably too quickly. He swallowed and winced as if it hadn’t helped. “Probably. Fine-ish.”
“Fine-ish?” She raised an eyebrow. “That’s your diagnosis?”
He attempted a grin. “Could be the TARDIS adjusting something. Could be me. Only one way to find out.”
The unsettling hum deepened as they walked to the sickbay. The corridors seemed longer, subtly shifting under the lights. They passed the archway that should have led to the sickbay, only to find another corridor, identical to the one they just left.
Donna frowned. “Didn’t we just…”
“Yes,” the Doctor said quietly. “And no. She’s… rearranging herself.”
“Why?”
He pressed his palm to the wall. The coral felt warm, almost feverish. “I don’t think she knows she’s doing it.”
The next turn opened into the library. Then, impossibly, the console room again. The hum slid lower, into something rhythmic. Somewhere deep in the ship, the Cloister Bell tolled, but the note was wrong. Warped.
A woman’s voice threaded through it, faint and urgent. “Donna…”
Donna froze. “Someone just said my name.”
The Doctor went very still. “I know that voice.”
“Who is it?”
He swallowed. His throat felt raw. “Someone who isn’t here anymore.”
He leaned against a coral strut. The surface was slick, beaded with red-gold condensation.
“She’s sweating too,” Donna said.
He nodded slowly. “Defensive reflex.” His fingers trembled as the coral twitched beneath his palm. He hissed and pulled back.
“Sickbay. Now.”
The lights in the room buzzed weakly.
The Doctor braced himself against a console, breathing too fast. He dragged a hand across his mouth, then frowned at the dryness it left behind.
Donna shoved the scanner into his hands. “You’re flushed. You need to drink something.”
“No time for tea, Nurse Noble,” he said, waving it off. “We’ve got a sentient forest and spores and…”
She interrupted him. “Your lips are cracked. Your hands are shaking. You’re dehydrated.”
He blinked at her. “I am not…” He paused. Licked his lips again. “Oh.”
“Drink,” she said flatly.
He swayed. His gaze unfocused for a second. “Water…” The word slipped out soft, almost fond. “Stay.”
Donna stiffened. “Doctor?”
He blinked hard and forced a smile. “I mean, yes. Water. Hydration’s essential. Hydration’s brilliant.”
“It’s not funny.”
“I’m fine!” he insisted, turning back to the console. As he moved, fine red dust drifted from his hair, glimmering with gold.
Donna’s voice shook. “What is happening to you?”
He didn’t answer.
Inside his veins, something itched. Threads were pulling tight, knitting him to the ship. The lights flickered. The hum deepened. Every time the TARDIS pulsed, so did he.
A crack opened along the coral near the scanner, leaking a slow line of red-gold fluid.
He reached toward it and froze. The liquid throbbed in perfect rhythm with his heartbeat. “Oh,” he whispered. “That’s not good. I think we’re both infected.”
Donna’s eyes widened. “You mean it’s in her too?”
The Cloister Bell tolled again, softer now. His own voice whispered through it: “Stay. Be warm.”
Donna grabbed his sleeve. “We need to get out.”
He shook his head, trembling. “If we leave her, she’ll die.”
“Doctor, if we stay here, we die.”
He met her eyes. After a long moment, he nodded once. “Right. Run first. Save her later.”
They sprinted through the shifting corridors, the ship’s heartbeat hammering in time with the Doctor’s.
The walls breathed around them, roundels expanding and contracting as faint red motes drifted in their wake. The air grew heavy, damp with the smell of soil and ozone.
By the time they burst into the console room, the coral struts were streaked with red filaments, crawling beneath the surface like veins under translucent skin.
The Doctor skidded to the controls and slammed the controls. “There!”
The doors shrieked open.
Heat and spore-thick mist surged in, wet against their faces. And, just standing there, dozens of them, maybe hundreds, were standing in a loose ring around the TARDIS like an audience that had already found their seats.
Donna froze. “They’re not attacking.”
“No,” the Doctor whispered.
He tilted his head.
There was a low vibration under everything, familiar and wrong at the same time. Then the sound shifted, resolving into something uneven, and layered. Breath that was caught and released, distant tones that slid against one another, never settling. A rhythm that rose and fell, faltered, then tried again, like something alive, practising how to be heard.
The Doctor’s gaze unfocused. His head tipped slightly, as if his body had recognised the pattern before his mind had.
“Oh,” he breathed. “That’s new.”
Donna grabbed his sleeve. “What is?”
“It’s a song,” he murmured. “Every filament, every host, joined.” He frowned faintly. “And also, instruction.” He winced. “Loud instruction.”
Donna didn’t hesitate. “Yeah, well, I don’t take orders from mushrooms.” She grabbed his hand.
His skin burned under her grip, fever-hot, his pulse racing against her palm.
They ran.
A sustained tone followed them, drawn out and layered, breath pulled through countless hollow bodies at once. The pitch wavered, split, rejoined. A chord searching for itself.
"Come."
"Stay."
The note shifted, resolving at last.
"Be warm."
Headlights cut through the mist they were running through, and a ground-crawler burst into view, skidding sideways as its treads bit into the loam. Its hull was streaked red, scarred with corrosion.
A hatch slammed open.
A woman in a biosuit leaned out, voice distorted through her respirator. “Get in!”
Donna turned, just in time to see the Doctor stumble. He sagged, one hand clamped to his temple. Red-gold dust smeared his jaw, glittering faintly where a filament had broken the skin.
“Oh no you don’t,” she muttered, catching him before he fell.
“Donna, I’m…” His voice faltered, distant. “It’s… loud.”
She hauled his arm over her shoulders. “I know. Keep up.”
The woman’s gaze snagged on the glow at his cheek. She hesitated. “He’s infected.”
“And he’s still coming,” Donna shot back. “I’m not leaving him.”
For a moment, the woman weighed it. Then she swore and reached out, dragging them both inside.
“Close it! Now!”
The doors slammed shut as shapes surged out of the fog, pounding against the hull. The crawler lurched forward, engines screaming as it crushed fungal stalks beneath its treads.
The Doctor sagged against a wall, eyes unfocused, his head tipping as though listening for the next beat.
The roar of the engine settled into a rhythm. Steady. Regular. Except, there was something more. Something lower, and slower, that slid under the engine’s growl and threaded through it, bending the pitch just enough to be felt in the chest.
“Can’t you hear it?” he whispered.
Donna tightened her grip on him.
The crawler lurched to a halt at the edge of a ridge.
Beyond the floodlights, the land fell away sharply into a fog-choked basin. Far below, the red forest spread like a living carpet, its bioluminescent pulses dulled by distance. Somewhere down there, swallowed by mist and growth, the TARDIS waited.
On the other side of the crawler, the ground stretched out flat and bare. A rust-coloured plain ran to the horizon, empty and wind-scoured, offering nothing but exposure.
The base clung to the ridge between the two. A last, fragile line of order.
Just beyond the flickering perimeter, a soldier was wrestling with a tarp.
“Careful,” someone snapped.
The soldier swore and jumped back as the tarp slipped, revealing a cargo cage beneath. Its bars were twisted and slick with dried sap, the metal dulled as if something corrosive had breathed on it for too long.
Donna leaned forward. “What is that?”
One of the soldiers on guard shifted his weight. “Used to be our base support animal,” he said.
The driver grimaced. “Poor thing got caught out during the first bloom.” He swallowed. “Ate the nutrient flow specialist before we could get the lockdown in place.”
Donna stared. “Ate … You mean it…”
“Wasn’t its fault,” the soldier cut in quickly. “It went wrong. Everything went wrong.”
The Doctor crouched beside the cage, peering through the twisted bars. Beneath the tarp, something moved.
A slow, uneven shudder, accompanied by a sound that might once have been a pitiful whine.
He raised the sonic and let it hum softly. The device’s tone wavered, flickered, then steadied. His expression tightened. “Not alive,” he murmured. “Not dead either.”
The tarp shifted again.
This time, he felt it more than heard it. A faint vibration underfoot. A pressure change in the air. The sound didn’t carry so much as align, brushing against the rhythm he’d felt in the forest below.
“It’s holding a note,” He added quietly. “Looking for something to harmonise with.”
Donna’s stomach turned. “That’s sick.”
He looked up at her, eyes shadowed. “No. Just lonely.”
The woman in the biosuit gestured sharply toward the airlock. “Inside. Please.”
As the hatch sealed behind them, the tarp over the cage stirred once more. From beneath it came a damp, uneven exhalation, half sigh, half growl, the sound slipping briefly into tune with something far below the ridge.
Inside the base, the air smelled of bleach and mushrooms. Generators throbbed beneath the floor, their rhythm uneven, like a heart working too hard. A half-functional server bay occupied one corner; consoles blinked dimly like tired eyes. A handful of scientists moved through the space, masked and hollow, too worn down to look surprised by anything new.
The woman from the crawler stripped off her gloves with shaking hands. “Dr. Miren Kael,” she said. “Chief Mycologist and Terraforming Director of Ephyra-5.” Her gaze caught on the faint spore stain at the Doctor’s collar. “And you are?”
“I’m the Doctor,” he said.
She waited.
“Just… the Doctor.”
A flicker of confusion crossed her face.
“And Donna Noble,” she said. “Temp.”
Miren blinked. “Temporary…?”
Donna gave a tight smile. “Everything is these days.”
Miren held that for a moment longer than was polite, then let it go. “You were in a fresh Myrdaceps bloom zone,” she said, all business again. “You’ve got luck on your side.”
The Doctor managed a thin smile. His mouth was dry; he swallowed before speaking. “Luck. And we did some very fast running.”
“You’ve seen hosts?”
“Up close,” he said.
Donna folded her arms. “They sounded like they’re doing a recruitment campaign.”
Miren’s jaw tightened. “They are.”
The Doctor drifted toward a console, scanning the readouts. His hands trembled as he adjusted the settings, but his movements were precise and careful. “Myrdaceps,” he murmured. “Self-spreading mycelial matrix. Adaptive learning. Designed for eco-rebalance.” He paused, brow furrowing. “Hm. Ambitious project.”
“That’s the official designation,” Miren said. “The colonists called it Nostura.”
He looked up despite himself, interest flickering through the pallor. “Old dialect. ‘The one that listens.’”
Miren nodded once. “It was meant to listen to the planet. And it did. The whole planet.” Her voice roughened. “Including us. Learned our voices. Our thoughts. Our memories.”
Donna let out a slow breath. “So, what? You built a fungus that wanted to be human?”
“It wanted to be everything,” Miren said. “And it didn’t stop there.”
“It found a carrier wave, didn’t it?” he asked quietly. “Resonance. It learned to speak in patterns humans don’t question. Music. Rhythm. And now it’s using that wave.”
“It hums at you till you give in?” Donna asked.
Miren’s shoulders sagged. “And eats you.”
Silence settled, broken only by the generators and the faint pulse of the quarantine field beyond the walls.
Then Donna noticed the Doctor’s hand, white-knuckled on the console. “You’re still shaking.”
He pulled it back slowly, flexing his fingers. His lips were cracked now; he wet them absently.
“Adrenaline,” he said. “Bit of dehydration.”
Miren watched him for a long moment. “Symptoms, but without visible filamentation,” she said finally. “No cognitive slippage. That’s… unusual.” She gestured weakly. “You both need scans. If you were exposed that long…”
She paused, then looked pointedly at the Doctor.
“You’re probably infected.”
Donna nodded once, brisk. “You heard the doctor, Doctor.”
He tried to smile again. It faltered, just slightly. “You’re going to make me lie down for that, aren’t you? Even though you already know?”
Miren’s gaze didn’t soften, but something like professional respect flickered there. “We scan and we test,” she said. “We let the data tells us.”
The infirmary hummed softly as diagnostics ran their slow loops. Donna sat on the edge of the examination table, legs swinging, watching Miren work the scanner with methodical precision.
Miren studied the display, then exhaled slowly. “You’re clear,” she said. “No filament growth. It’s not taking root in you.”
Donna blinked. “You’re sure? Because I definitely inhaled half a forest back there.”
“I’m sure.” Miren tapped the screen once. “But I don’t know why. Natural immunity, perhaps. Or simple incompatibility. Or maybe lack of direct contact, like he has had.”
Donna’s gaze slid sideways to the other diagnostic table, where the Doctor lay back beneath the red glow of the monitor, hands folded neatly on his chest.
“Lucky me,” he muttered, not looking up.
The display above him jittered - pulse irregular, hydration markers flashing warning amber. The scanner chirped sharply, and Miren’s expression changed.
A filament map bloomed across the display: delicate, branching threads threading through his bloodstream like living coral.
She turned the screen slightly so they could see. “I’m sorry. It’s happening,” Miren said. “Neural-field integration has begun.”
Miren zoomed in on a part of the readout. “The filaments feed on water. They draw moisture directly from living cells to propagate.”
The Doctor finally looked at the screen. “Ah,” he said softly. “That would explain the thirst.”
“The fungus is drying out?” Donna said.
“From the inside,” Miren confirmed.
The Doctor pressed a hand to his chest, breath shallow. “Every breath accelerates it. Fantastic design. Horrifying, but very efficient.”
“Can you maybe not admire it?” Donna snapped.
He gave a faint, apologetic shrug, and coughed. Tiny red flecks spattered his sleeve.
“Doctor…”
He waved her off, jaw clenched. “I’m good.”
Miren hesitated. “We can attempt rehydration,” she said carefully. “It may slow the progression.” She paused, studying him. “But it’s your call.”
The Doctor met her eyes. The familiar brightness wavered, and for the first time since they’d landed on Ephyra, the joke didn’t come.
He swallowed. “Do it.”
With practiced hands, Miren connected the IV, and the clear fluid began to flow.
Almost immediately, the veins around the needle flared crimson. The Doctor arched off the table with a sharp gasp. The liquid hissed under his skin, as if was poured onto hot metal.
“Stop!” Donna shouted, grabbing the line.
Miren cut the feed instantly.
The Doctor collapsed back, shaking, breath ragged. “It’s… faster” he rasped. “Rooting faster. It’s … paying attention.”
Before anyone could speak, an alarm blared elsewhere in the base, sharp and urgent.
Miren swore under her breath. Her comm crackled to life — breach on the lower perimeter—
She looked at them both. “I need to deal with that,” she said. “Stay here. Do not leave this infirmary. I’ll be back as soon as I can. And, for what it’s worth, I’m really sorry.”
She keyed the door shut behind her, and the lock engaged with a solid clang.
The silence that followed was heavier than the alarms.
Donna drifted toward the window. Beyond the quarantine field, the valley glowed red with fungal haze. Down below, the TARDIS stood among the trees, her blue light veined with faint crimson, pulsing like a wounded heart.
“She’s glowing,” Donna whispered.
The Doctor turned his head slowly. “She’s fighting,” he said. “I can feel her trying to hold the line.”
Donna swallowed. “Can she win? Can you?”
He didn’t answer.
The hum of the infirmary shifted. Not louder. Not softer. Just… different. The Doctor went still. He tilted his head, the way he had in the forest. “Oh,” he muttered.
Donna turned. “Oh what?”
“It’s about to change,” he said.
“What is?”
He closed his eyes. “The tone.” He sighed, almost contented. Suddenly, his eyes snapped open again, pupils blown wide. “Oh… the temporal field’s wrong,” he whispered. “The future is… blank.”
Donna steadied him, her hand on his shoulder. “Say what?”
“Like… erased.” He gripped the edge of the diagnostic table. “Donna, I always know what comes next. I feel time. All the branches, all the possibilities. But now…”
“Breathe,” she said softly, gripping his hand. “Breathe. Just tell me what to do next.”
“I can’t!” His voice cracked, raw. “I don’t know what next is anymore!”
For the first time since Donna had met him, the Doctor looked truly afraid.
He pressed both hands to his temples. “It’s like someone’s taken a scalpel to the part of me that knows when.”
The lights flickered. The hum dipped an octave lower. And then, for a heartbeat, his whole world fell away.
He was standing in the same room, but the air was cold and still. The monitors were dead. Donna lay motionless on the floor, eyes open and unseeing. There was silence, absolute and endless. A single red filament wound through the air like a thread of smoke.
He gasped.
Donna’s face swam back into focus. “Doctor?”
He stared at his hands, shaking. “Dead-end branches overlapping,” he whispered. “That’s not… that’s not how my mind is supposed to work.”
The hum intensified, and deep down inside his mind, the song returned.
Soft, patient, perfectly in time with his pulse.
He squeezed his eyes shut.
It kept playing.
It already knew the rhythm.
Night on Ephyra-5 came without stars. The red haze had thickened until the dome glowed like a lantern sunk deep underwater.
The Doctor was restless.
He paced the room, tracing the inner railing, running one hand over a console, fingers drifting absently over sensor readouts he wasn’t really reading. Every few seconds, his head tilted, as if he were listening for something just beyond the range of sound.
Donna hovered a few steps away, watching him out of the corner of her eye.
Miren finally emerged back from the inner corridor at a brisk pace, tablet clutched tight against her chest. She looked pale, her movements clipped, breath slightly off-rhythm.
“It’s accelerating,” she sighed.
Beyond the quarantine field, the Myrdaceps-infected were everywhere now.Their silhouettes moved through the haze — no longer shambling, no longer erratic. They advanced and withdrew in a loose formation, testing the barrier with rhythmic precision. Every few minutes they stopped together, heads tilting in the same direction, listening.
Miren brought up the readouts. “They’re coordinating. The mycelial network must be sharing data in real time. This is brand new behaviour. And it started when you…” Her eyes flicked to the Doctor, and she paused.
The Doctor walked up beside her, his skin grey-ashen under the emergency lights. “They’ve worked out how to be efficient,” he said softly. “No waste. No chaos. Just determination.”
Donna watched the shapes outside circling closer and closer. “Sounds like you on a bad day.”
Miren turned her tablet so they could see. “The coordination comes from a central node. The root-heart. That’s where the primary matrix was seeded.”
Donna frowned. “Central, so, a hive mind?”
“Closer to a nervous system,” Miren said. “The original terraforming seed was buried half a kilometre below the basin. It was meant to integrate with soil sensors, recycle toxins, rebalance groundwater.”
She swallowed. “But it kept growing. Spore to spore. Host to host. And now I think it’s just one organism. But, that heart’s still there, pulsing under the surface. Everything up here listens to it.”
The Doctor’s gaze fixed on the horizon, where the TARDIS pulsed faintly through the fog, her blue glow veined with red.
“A central consciousness,” he muttered. “Cut that off, the rest collapses.”
Miren powered up her portable sequencer. “If we can reach it, I can map the genome. Maybe find a counter-sequence. Something to disrupt the signal.”
“Don’t destroy it,” the Doctor said quietly. “Just… quiet the song.”
Donna shot him a look. “You’d rather talk a fungus to sleep than kill it?”
His smile was thin, but genuine. “Wouldn’t be the first time.”
A sudden hiss shivered through the dome walls. The quarantine field dimmed to a sickly pink. Beyond it, the infected pressed closer – their faces luminous from within, mouths moving in perfect unison.
Their voices came as one.
“Come.” They sang together. “Come closer.”
The Doctor swayed. The rhythm pulsed in his skull. His lips moved with the echo. “Come… closer…”
Suddenly Donna couldn’t breathe in the room anymore. She turned away before the sound could settle any deeper, pushing through the nearest hatch and out into the open air.
Spores danced through it, but she breathed it in anyway. “Fresh air,” she muttered. “Sort of.”
The ridge wind carried the tang of iron and rot. Fog curled around her boots, red in the glow of the quarantine fields.
Then she heard it.
Not melody — not properly, at least. More tone and pulse: a low, uneven rhythm rising out of the ground itself. A heartbeat made of wind and soil.
Donna frowned. “What is that?”
The sound deepened. Layers folded beneath it, harmonics threading together like voices humming far underground. It wasn’t frightening.
It was… beautiful. Gentle. Reassuring. The kind of sound that made you want to stop moving. Stop thinking. Just stand there and listen.
Her mouth felt dry. She licked her lips, surprised by the rasp of her tongue.
“Oh no,” she whispered, as fear snapped through her, sharp and cold.
She stumbled back into the airlock and slammed the seal. The sound vanished with a hiss of equalising pressure, leaving only the hum of the base.
Inside, the Doctor stood at the med console, one hand braced against it, eyes unfocused. “You heard it,” he said quietly.
She jumped. “You could at least pretend to notice when I’m about to have a panic.”
“I could feel it in you,” he murmured. “The song.”
“Yeah, well, it’s catchy, in a really horrible way.” She swallowed. “Run another scan on me.”
He hesitated. “Donna…”
“Don’t you ‘Donna’ me.” Her voice shook, but she didn’t back down. “If this thing’s crawling through your blood and making you time-blind, I need to know if it’s doing the same to me. Or worse.”
For a moment, he just looked at her. Then he turned to the console.
The scanner hummed, bathing her in soft blue light. His hands trembled as he adjusted the settings.
The readout flickered.
Faint filaments traced through her tissue. Delicate, symmetrical, like frost blooming across glass.
He frowned. “That’s… different.”
“Different how?”
“They’re not infiltrating your cells.” His brow creased. “They’re… flowing.”
“Flowing? Doctor, sentences please! Don’t make me guess!”
“Following the electrical field of your brain waves.” He hummed. “Aligning to it.”
“Well,” Donna said dryly, throat burning with dryness, “that’s NOT comforting.”
He tried to smile, weary, but kind. “But you’re holding your own. Whatever it’s trying to find or do, it doesn’t seem to be successful.”
She huffed out a small, defiant laugh. “Good. I’ve had enough weird blokes trying to change me already.”
His mouth twitched, the ghost of a grin. “You’re impossible, Donna Noble.”
“Yeah,” she said softly. “That’s what keeps me ali—”
She stopped talking.
Her eyes had drifted to his hands.
They rested on the atmospheric control console. Not gripping for support. Adjusting settings. Settings he had no reason to be touching.
“Doctor,” she said slowly. “What are you doing?”
He looked down.
Confusion flickered across his face. Genuine. Unfeigned.
“I… don’t know.”
His fingers moved again, precise and practiced, beginning to disengage the quarantine airflow.
Donna moved instantly, grabbing his wrists and pulling them back. “Nope. Absolutely not.”
He staggered, breath hitching. “I wasn’t trying to… I didn’t even realise—”
His vision fractured again.
The dome was breached. Miren was gone. Everyone was gone. Except Donna. She stood perfectly still, eyes gone white, fungal threads coiled through her mouth, her chest rising and falling in perfect time with the song.
The image blinked out.
He swayed. “You all die?” he breathed. “Or… no, you already did, didn’t you?”
“Doctor.” Donna caught his arm, holding him upright. The warmth of her touch dampened the tremor beneath his skin.
He dragged in a ragged breath. “Nothing. Echo. Wrong moment. I keep… slipping.”
Sweat beaded at his temple. Beneath the skin of his throat, a faint red shimmer traced along a vein — red shot through with gold.
Donna gripped his shoulders hard. The shimmer flickered, then dimmed. His breathing slowed under her hands.
“Oi,” she said, fierce and shaking. “Stay here.”
He blinked, refocusing on her face. A faint grin flickered, and he was almost himself again. “Always a team,” he said hoarsely. “You and me.”
She shoved a pack against his chest. “Then let’s go end this before you dry up completely.”
Miren snapped her sample case shut, voice clipped. “The maintenance tunnel starts just beyond the ridge. We follow the old nutrient channels straight down to the root-heart.”
The Doctor nodded, though the tremor in his hands betrayed him. “Right,” he said. “Let’s do this.”
They stepped out through the dome’s side hatch, and the night hit them like breath from a furnace - humid, metallic, alive. Below them, the infected still ringed the valley, humming in layered waves, the Myrdaceps song rising and falling.
They were only a few metres from the tunnel entrance when something small broke away from the silhouettes, darting up the ridge toward them. At first Donna thought it was a child, but then the fog thinned.
A round-bodied creature, no bigger than a terrier, trotted toward them on soft paws. Its fur shimmered with pale blue bioluminescence, pulsing gently like comfort. It had big black eyes, a button nose – basically, it was a living and breathing plush toy.
Miren inhaled sharply. “Native species. We call them comfort-kin. They bond to cortisol spikes.”
Donna blinked. “Meaning…?”
“They come when someone’s scared or stressed,” Miren whispered.
Donna turned toward the Doctor.
He was staring fixedly ahead, breath unsteady, pupils blown wide.
The creature padded right up to him and rested its tiny paws against the flickering quarantine field. It whined - soft, plaintive, heartbreakingly normal.
Donna felt something crack in her chest. “Oh, you poor little…”
Then its fur rippled.
A vein of red light threaded from its ear down its spine, blooming like frost. Its eyes clouded to milky white. The bioluminescence shifted from blue to a sickly rose.
The comfort-kin tilted its head.
The Doctor’s head tilted too - the same precise angle.
“Warm…” it said. Two voices overlapped now: one childish, one ancient. “Be warm. Please stay.”
The Doctor took one step forward before he realised he was moving.
“Hey. No.” Donna caught his sleeve, gentler than she meant to be, as if calming him rather than stopping him. “Eyes on me, Spaceman.”
He didn’t look away from the creature. His breath hitched, a sound too close to grief. “It’s scared,” he whispered. “It’s still in there. I can feel it.”
The comfort-kin pressed both paws harder against the barrier, leaving faint red smears. For half a heartbeat its fur flickered blue again, and then the infection surged back, red overtaking everything.
“Doctor,” Donna said, firmer now, tightening her grip. “You can’t save it.”
His voice came out raw and small. “I know. That’s the bit I hate.”
The creature’s head tilted the other way, unnervingly precise. “Come,” it said gently. “Come with us. Come home.”
A spike of pressure flared behind the Doctor’s eyes. The world stuttered - half a beat missing. His fingers twitched, echoing the cadence under his breath. “Come…”
Donna slid her hand into his, solid and warm. “Stay here with me.”
The shimmer beneath his skin dimmed. It was not gone, just quieter. He swayed, lifting a hand to his temple as the headache ebbed.
Miren cleared her throat, voice shaking. “We need to move. Now.”
The creature stood very still a moment longer. Then it turned and padded back into the mist, joining the waiting silhouettes without a sound.
The Doctor didn’t quip. Didn’t smile. He just stood there, breathing shallow and uneven, eyes fixed on where the creature had gone.
Donna squeezed his hand. “We’re gonna fix this. And then you can be sad about plushie-zombies, yeah?”
He huffed a sound that might have been a laugh. “Yeah.” Then, so softly she almost missed it, he added, “I hope it won’t feel too alone.”
The tunnel dropped steeply, its walls slick with translucent growths that pulsed faintly under their torches. The deeper they went, the hotter the air became: thick, metallic, tasting of copper and damp stone.
Every footstep echoed twice, as though the cavern listened and answered.
Sometimes the echo arrived half a beat early.
“Brilliant,” Donna muttered. “Feels like walking down someone’s throat.”
“Close,” Miren murmured behind her. “These channels used to carry nutrient gel for terraforming.”
The Doctor’s voice floated back, thin and oddly bright. “I think they’ve been…” He faltered. “They will be repurposed. Were. Are.”
He kept moving, torch wobbling slightly in his shaking hand, not seeing Donna’s worried glance.
The passage began to open out. The ceiling lifted. The air changed.
And without meaning to, the Doctor slowed.
His torch dipped toward the vast red mass at the cavern’s centre. His free hand lifted with the palm half-open, fingers loose, as if expecting something to settle there.
Donna saw it before he did.
“Doctor…”
He frowned, as if surprised to find his hand raised at all, and lowered it quickly. “Sorry,” he said, too fast, and started walking again.
At the cavern’s heart rose the root-heart: a massive mound of braided mycelium, swelling and contracting like a living organ. Dull crimson light throbbed through it. Filaments crawled up the walls, vanishing into the black dome overhead.
Donna heard the thoom of it a fraction of a second before she felt it. The vibration travelled up through her boots and into her teeth, setting her jaw buzzing. Her chest tightened, breath catching before she realised why.
“I really don’t like this,” she said quietly.
Miren had stopped dead.
She stared at the root-heart, her grip tightening on the scanner until her knuckles went white. “It’s bigger,” she said.
Donna glanced at her. “Than what?”
Miren swallowed. “Bigger than a few hours ago.”
The Doctor stepped forward, bathed in red glow. His pupils shrank to pinpricks. His breath stuttered - Donna heard it catch.
“Hey,” she called softly. “Stay with me.”
He lifted a trembling hand toward one of the hanging filaments. His fingers brushed it.
The entire cavern shuddered. A low, yawning, ancient moan rolled through the root-heart.
More filaments lifted, drifting toward him like strands drawn to static.
“Don’t you dare,” Donna warned, stepping close.
He whispered, “But they’re calling. They’re asking to join. Asking me to show them the next minute. And I can’t see it, Donna. I can’t see anything.”
Donna stepped into his line of sight and didn’t move. She waited until his eyes found hers — unfocused at first, then sharp with effort.
A thin red line trickled from his nostril. Rust-coloured blood, speckled with gold.
“You’re bleeding.”
He blinked, dazed. “Temporal pressure. All the futures… gone. Just this one moment shouting at me. A Time Lord’s mind… isn’t… won’t be…” He closed his eyes.
Filaments brushed his sleeve, then his wrist, curling gently as though claiming him.
The glow beneath his skin flickered in answer.
Donna lunged, grabbing his coat and yanking him backward.
The moment she touched him, the glow beneath his skin dipped, as if her contact grounded him. He gasped, and his eyes cleared for half a heartbeat.
“Don’t let go,” he breathed, voice cracking.
“I’m not,” she snapped, tightening her grip on his coat. “You hear me? I’m not losing you to a mushroom.”
More tendrils rose from the root-heart, unspooling slowly, tasting the air. They drifted toward him with awful delicacy, like hands that already knew his shape.
Behind them, Miren was moving fast.
She knelt, stood again, cursed under her breath as her sampler sparked against the living surface and skidded away. “No, no, stay still, damn you!” She recalibrated and stabbed the mycelium again. The mycelium closed around the probe instantly, sealing like fresh flesh. “It’s regenerating faster than I can cut…”
The Doctor gasped. His spine arched as the rhythm surged through him, red light flaring beneath his skin. His voice came wrong now: deeper, stretched, threaded with resonance from the cavern itself. “We are aligned,” he whispered. “The rhythm… it’s everywhere…”
Donna moved without thinking. She put both hands on his jaw, thumbs pressing hard just below his ears.
“So loud…” His voice faltered mid-word.
“No,” she said, low and furious.
His body jerked, caught between her grip and the reaching filaments. Another thin line of blood slipped from his nose, dark against his skin, and staining the front of his suit.
Miren swore sharply. “I can’t get a clean extraction. Every time I cut, it learns. It’s adapting to me!”
Another tendril brushed the Doctor’s wrist.
He shuddered, breath breaking. “Donna… it feels like time’s folding in on itself. Like everything’s happening at once…” For half a second, he felt certain his next breath had already happened.
“Miren!” Donna shouted.
Miren lunged again, plunging the needle into the living mound.
The cavern convulsed. Every filament tightening in a single, shuddering breath. Spores rained down like glittering red snow.
One landed on Miren’s exposed wrist. She screamed as her skin blistered instantly, red threads racing up her veins like cracks in glass.
“No, no…” she gasped through clenched teeth, forcing the sampler deeper. “Almost… got it…”
The Doctor’s head jerked, and his eyes unfocused. “You could stay, Donna. No fear. No loss. No time.”
Donna grabbed fistfuls of his coat and yanked him toward her, stopping just short of collision. “No.” Her voice shook, but it was fury, not fear. “Hey. Oi! Doctor. Look at me.”
His glazed eyes flickered, unfocused. “Donna…” the other-voice whispered through him, sweet as rot, warm as soil. “Stay. Be warm…”
“Look at me,” she said fiercely. She leaned in until their foreheads touched.
He could feel her breath — fast, human, real – and his focus snapped to it like a lifeline. A tremor ran through him. The red glow pulsed once, twice, and then faltered. He inhaled sharply, like surfacing from deep water. The red retreated from his eyes like tide going out, leaving tired, frightened brown behind.
Donna exhaled, shaking. “That’s it. Come back to me, Spaceman.”
The filaments around him recoiled, shrieking with a metallic edge that scraped the bones.
He winced, touching his temple. “Ow. Brain’s ringing. Like someone smacked me with a frying pan. From the inside.”
She kept her hands on his shoulders, grounding him. “Sounds like a normal Sunday morning hangover. Don’t drift off again, eh?” She pointed at the kit. “Antidote.”
His laugh was ragged, breathless, but him. “Right. Yes. Antidote. Brilliant plan.”
Miren collapsed to her knees, red-webbed veins spreading like roots beneath her skin. She thrust the half-filled vial at Donna with shaking hands. “Core sample… contaminated… but try…”
The Doctor grabbed the vial, his movements clumsy but determined. “Purity is overrated anyway,” he muttered. He jabbed the extractor in his own arm, mixing his blood with the sample.
He swayed. “Rewriting the growth code… but it needs a stabiliser…Donna!”
“What?”
“Your blood - whatever’s shielding you. Resonance, I don’t know. You’re a good grounding pattern.” He thrust her the sampler.
She didn’t hesitate and jammed it into her arm. She hissed through as the extractor did its work, and then she tossed him the cartridge.
He caught it badly, nearly dropping it, but managed to click it into place. The fluid inside swirled gold-red-violet, swirling like a tiny storm.
Donna crouched beside him, breath coming fast. “Tell me what else to do.”
He looked up at her, and for a moment his expression was heartbreakingly young. “When I use this,” he whispered, “It’ll try to get me again. Don’t let it.”
“What does that…”
He plunged the device into the root-heart. As the point of the needle pierced the mycelial flesh, the entire cavern exhaled.
It sang.
Not like music. Not like anything meant for human ears. A layered chorus, hundreds - thousands - of voices resonating through bone and air.
JOINJOINJOIN
The mound arched toward him like something waking. A blinding white light burst outward, brief and swallowed almost at once. The air stopped, as if a hand had clamped over the mouth of the world.
Donna barely had time to register it before the Doctor convulsed.
His veins flashed red, then gold, then in dizzying pulses. His mouth opened in a sound that wasn’t quite a scream, wasn’t quite speech — something being pulled out of him by something enormous and dying.
The Myrdaceps song surged for a heartbeat, in a final, aching refrain:
STAYSTAYSTAY
and then—
Nothing.
No crescendo. No explosion. Just the sudden, unbearable absence of voices that had filled the air for days. The cavern’s living glow dimmed to the faintest ember, like coals under ash. Filaments that had craned toward them moments ago sagged, colour leeching from red to pale grey. The damp heat evaporated.
Donna felt the Doctor sag against her. His chest rose once, twice, then steadied. The tremor melted from his shoulders. He blinked, and for the first time in hours his eyes were brown. No red shimmer. No doubled reflection. Just brown.
He drew a long, shuddering breath. “Oh. That’s better.”
Donna crouched, hands framing his face. “Talk to me. What’s better?”
He pressed his palm to his temple, testing the silence inside his mind. “The noise is gone. The pull. The… ah… cosmic lullaby of mould.” He inhaled again, wonder flickering across his features. “And, wait… listen…”
Donna listened. There was nothing. She shook her head.
“That’s the point,” he said softly. “The song’s gone.” His eyes sharpened like a lens snapping into focus. “Oh. Oh yes. And there you are.”
“Who is where?” Donna asked.
“Time.” His grin cracked wide and giddy. “It’s back. All the threads, all the flow… oh, Donna, I thought I’d lost it. Everything was stuck. Everything was still. But now,” He laughed, shaky. “It’s messy and bright and moving again.”
Donna let out a breath she didn’t realise she’d been holding. “Good. Because one of us needs to know where we’re going.”
Behind them, the root-heart pulsed faintly gold - not red. Breathing softly. No longer hunting. The air finally felt cool.
Donna dusted her hands, leaving streaks of dying spores that faded as they fell. “All right, Doctor. You saved the planet and scared ten years off my life. What’s next?”
He looked up at her, exhaustion and hope warring in his eyes. A faint gold shimmer still clung to his pupils.
“Now,” he said softly, “we go home.” He took a deep breath. He took a careful breath. “And see what state my old girl is in.”
The climb back through the tunnels was easier now.
There was no pulse in the walls. No whisper threading their thoughts. No pressure leaning in behind the eyes. Just the echo of their footsteps, and even that arrived a fraction too late, as if the sound were checking whether it was allowed to follow.
The Doctor told himself that meant the song really was gone.
His head still throbbed dully, like an ache left behind after a fever breaks. His mouth was dry again - just enough that he swallowed more often than he meant to. Time felt present, solid, threaded properly back into itself… and yet every so often it slipped, just for a blink, like a frame dropped from a film.
The red haze had thinned by the time they reached the ridge, and a scrap of real sky hung overhead - bleached and exhausted, but blue.
Miren limped ahead, clutching her case. Donna kept an arm braced under the Doctor’s elbow; he leaned on her more than he meant to, breath shallow, skin papery-thin and still streaked with pale red veins that hadn’t quite faded.
They reached the clearing.
Donna sucked in a breath and froze. “Oh… Doctor. No. No, no, no—”
The TARDIS was no longer a simple blue box.
She had been growing.
Coral panels had swollen outward like ribs under tight skin. Red mycelial threads veined her surface, pulsing gently, rhythmically, like root networks breathing beneath soil. Her windows glowed a deep ochre-red, all warm and wrong. At her base, filaments spooled into the earth, spreading outward like roots.
The Doctor staggered forward, reaching out with a trembling hand. Some of the filaments lifted toward him, reaching like children to a parent.
One brushed his cheek.
His breath caught, and then he gasped.
Not in pain.
In recognition.
“Oh, my poor girl,” he breathed, voice breaking. “She’s trying to talk to me.” He pressed his palm to the coral wall; it throbbed beneath his touch, warm and wrong.
Miren stared at her scanner, horror dawning slowly across her face. “The Myrdaceps didn’t die when the root-heart collapsed,” she whispered. “It fragmented. Migrated. A portion of the matrix relocated itself.”
He looked up at the TARDIS, hands shaking. “It needed a network. A telepathic field. And she was… here.”
The hum deepened to something warm, rhythmic, almost comforting. Almost.
Donna felt it in her chest before she heard it. “Doctor…” she said quietly. “She’s… singing.”
He nodded, swallowing hard. “But it’s not her song.” His voice roughened. “That’s them. Using her mind like scaffolding. Holding themselves together through her.”
Miren’s voice was barely steady now. “If it finishes integrating, she won’t just be infected. She’ll become a stabilising node. A queen structure.”
Donna’s head snapped between them. “You mean—”
“A new core,” the Doctor added grimly. “Mobile. Telepathic. Capable of spreading the Myrdaceps across time-space.” He closed his eyes. “And I did this. I brought us here.”
Donna grabbed his arm. “Stop apologising and fix her.”
He managed a thin smile. “She’ll fight us.”
“Yeah,” Donna said. “She’s stubborn.” She squeezed the Doctor’s hand. “Wonder who she got that from.”
The Doctor wiped his cheek where the filament had touched him. It left a streak of glittering red-gold dust across his skin. He didn’t even notice.
He stepped toward the doors, and they shuddered open slowly, as if pushing through thick water.
“Doctor…” This wasn’t the TARDIS – no. “Stay.” Rose’s voice, warm, familiar, and devastating drifted down the corridors. “You don’t have to be alone.”
Inside, red veins of mycelium webbed every surface, pulsing as if it were a heartbeat. The air smelled of burnt sugar and ozone.
Voices whispered through the walls, layered over one another until the room felt crowded.
“Doctor…” Rose’s voice again, closer this time. But strained. “Stay. Please. You don’t have to be alone.”
Donna sighed. “Oh, that’s wrong. That’s really wrong.”
Filaments quivered at his presence, recognised him, and reached out. Red threads slid from the console like living silk, winding up his arms, burrowing under the skin where old telepathic pathways waited.
“Doctor!” Donna warned, but it was too late. A wave of red light flared across his body, his veins glowing faintly gold-red, the infection recognising him on a deeper level.
A voice whispered through the TARDIS.
O u r s .
His knees buckled.
Donna caught him, bracing his weight with a grunt. “Tell me you planned for this!” she barked.
He managed a shaky grin. “Donna, when have I ever planned…further than thirty seconds… ahead?”
“That is NOT a comforting answer!”
He turned back to the console, fighting to focus through the rising song vibrating in every bone of his skull.
“Old girl…” He pressed his palms to the coral. “Listen to me. You’re not meant to root. You’re meant to run. You are bigger than this, bigger than any world. You are time, love. You don’t belong underground.”
The hum deepened, becoming uncertain and pained. The TARDIS wanted to answer him. But the Myrdaceps wanted him more, and tendrils lashed out again. One wrapped his throat. Another curled around his wrist, tightening.
Donna lunged forward. “Oi! Get off him!”
The filaments recoiled from her instantly, almost afraid.
The Doctor gasped. “Donna, you’re still… it’s destabilising them. Good… good… keep close…”
Miren’s sequencer pinged. “The dispersal compound is ready.”
“Then when I say now…” he choked, flinching as another filament burrowed against his collarbone, “Or roughly then-ish… no earlier! Actually earlier! No—no later—just—DON’T MISS!”
“That is not a plan!” Donna yelled. “When??”
“You’ll know when I do the thing!”
“What thing?!”
“That thing!”
And then he did the most Doctor thing imaginable: he shoved both hands deep into the infected coral and let the TARDIS take him.
Red light surged across his skin. His eyes snapped open - not human now, not anymore - burning red-gold as the song flooded him whole.
W e . A r e . O n e . S t a y . B e . W a r m .
The words vibrated the room. The coral walls answered, swelling, pulsing harder, faster. Tendrils tightened around his arms and throat, drawing him closer to the console, to the heart of her.
Donna didn’t hesitate.
She hit him.
Not careful. Not restrained. With everything she had.
The crack echoed through the room.
His head snapped sideways. For a fraction of a second the light in his eyes shattered, the red fracturing, dimming, the brown bleeding back through like a bruise surfacing.
“Ow,” he croaked, stunned. “Blimey.”
His hands were still buried in the coral, fingers sunk deep, tendrils wrapped tight around his wrists and forearms. The Myrdaceps still held him - still inside him - shrieking now, furious, wounded.
Donna grabbed his face, forcing him to look at her. “You with me?”
He sucked in a ragged breath. Nodded once. Barely. “Mostly.”
“Good.” Her voice shook, furious and terrified all at once. “Stop disappearing on me like that.”
Miren stared at them, white-knuckled over the dispersal trigger. “Doctor?”
His voice was steadier now, though pain flickered across his face in sharp waves. “Do it. I’m still connected. I’ll be the bridge.”
The tendrils spasmed, sensing the threat. One coiled tighter around his throat. Another drove painfully into old telepathic pathways. He gasped, and his eyes flared again, the red clawing for dominance.
Miren fired the disperser.
Blue vapor exploded into the room, flooding the air in a freezing rush. It slammed into the red light, the colours colliding - blue against crimson, gold flashing between - until the console room became a storm of sound and colour.
The TARDIS screamed.
Not a noise — a cry. Ancient. Vast. The sound of a thinking thing in agony, echoing through bone and memory and time itself.
The Doctor convulsed, dragged halfway to his knees by the backlash, every nerve alight. Donna wrapped herself around him, anchoring him with sheer stubborn will.
“She’s fighting,” he choked. “She thinks… she thinks she’s protecting me…”
“Then tell her!” Donna shouted over the scream. “Tell her you’re safe!”
His breath came in shuddering pulls. Blood trickled from his nose, hot and metallic. The song still clawed at him — stay, stay, stay — but he pressed his forehead to the console anyway, hands shaking, voice breaking open.
“I’m safe,” he whispered. The words were small. Human. Terribly fragile. “I’m home.”
For a heartbeat, nothing happened. Then the tendrils hesitated. Just a flicker. A question.
He pushed on, voice rough with grief and love. “You don’t need to hold me.”
The blue vapor sank deeper, threading through coral and circuitry, riding the telepathic link through him, burning, cleansing, rewriting.
“You’re more than this,” he breathed.
The red light faltered and then collapsed inward.
The tendrils recoiled all at once, ripping themselves free with a sound like tearing silk. The console flared, red to white to gold, the light detonating outward in a blinding wave, and the TARDIS exhaled. A long, shuddering release.
Silence crashed down.
The Doctor sagged forward. The coral walls dimmed, cooling from fever-red back to brown gold - not pristine, not untouched, but hers again. Pale scars shimmered faintly where the infection had been.
Donna slid to the floor with him, heart hammering. “Oi. Spaceman.”
His chest rose.
Once.
Twice.
He groaned faintly. “Still… here…”
She laughed, breathless and wrecked, pressing her forehead to his. “You’re impossible.”
He blinked up at her, eyes finally just brown again. “Yeah.”
Somewhere deep in the ship, the TARDIS hummed - low, affectionate, and unmistakably grumpy.
Epilogue
Donna was in the kitchen, rummaging about for tea which she insisted was absolutely, certainly, definitely needed right now.
Good, he thought. She doesn’t need to see this bit.
He moved toward the coral wall behind the console, where the glow was faintest. The place she always gave him when he didn’t want to admit he needed it.
He knelt, slowly, carefully, and pressed both hands against the coral. It pulsed beneath his palms. Once. Weak, but present.
His voice came out barely above a whisper. “Hey. Old girl.”
A faint tremor answered him, like a heartbeat too tired to beat properly. He swallowed. “I should’ve heard you sooner.”
The coral dimmed, and a ripple of sadness brushed against his mind.
The Doctor closed his eyes. “You were shouting, weren’t you? From the moment we landed. You were trying to tell me it felt wrong. That the ground was wrong.”
The TARDIS flickered briefly.
“And I didn’t listen.” His voice cracked. “I was too busy being clever. You trusted me. And I nearly let you die. Worse, I let something else… use you. I let it speak with your voice. Touch your circuits. Crawl through your memories. That’s…” His throat closed. “…that’s unforgivable.”
A slow shudder of grief ran through the walls.
He rested his forehead against the coral, breath shivering out of him. The coral throbbed in a soft, tremulous pulse.
“No,” he whispered. “No, don’t you dare forgive me that easily.”
To his absolute surprise, the TARDIS sent another burst of emotion through the link, one that wasn’t forgiveness. It was affection. Worn at the edges, and fragile - but steadfast.
“Oh,” he breathed. “Oh, love…”
His shoulders shook. Once. Then twice. He didn’t sob, not quite. But his breath came ragged, like someone trying not to break in a room where no one should see him break.
A hand touched his shoulder.
Donna, still half-asleep, shuffled closer. “You daft alien,” she murmured. “You think I don’t know where you skulk off to when you’re hurting?”
He scrubbed at his face quickly. “I wasn’t…”
“Yes, you were.” She knelt beside him, wincing. “My knees are killing me, and I’ve still got more sense than you.”
He gave a wet laugh. “Donna, I nearly lost her.”
Donna rested her palm on the coral beside his. The TARDIS warmed beneath it instantly. “You didn’t,” she said simply.
“I should’ve…”
“Stop.” She shifted so she could look him full in the face. “You listened when it counted. You fought for her when it mattered. And she fought for you too. That’s what this is.”
He swallowed. His eyes were dark and too bright, but he listened.
Donna softened her voice. “I saw the way she wrapped those tendrils around you. Not to hurt you. To keep you. Because she didn’t want to lose you either.”
He blinked hard. “Donna…”
“And I saw the way you talked her back,” she went on. “Not like a pilot fixing a machine. Like someone coaxing a frightened animal out of a storm.”
The Doctor looked away, breath unsteady.
Donna squeezed his shoulder. “She’s not angry with you.”
“I’m angry with me,” he whispered.
“Yeah,” Donna said. “I figured. You’re good at that.” She leaned her head lightly against his. “But she’s alive. I’m alive. You’re alive. And whatever comes next? We’ll face it. Together.”
The TARDIS hummed, soft, warm, and forgiving, and the lights brightened like a heartbeat answering his.
The Doctor let out a long breath, cracked at the edges but steadying. “Together,” he echoed.
Donna bumped her shoulder against his. “Now come on. We need tea. And a shower.”
He huffed a laugh. “Yes, ma’am.”
She stood, offering him a hand. He took it, weight sagging more than he meant to.
“Easy,” she said gently. “Still crispy round the edges?”
“A little.”
“Yeah,” she said quietly. “Figures. You don’t come out of something like that spotless.”
He squeezed her fingers. “Thank you, Donna Noble.”
“Oi. Don’t go getting sentimental. I’m overtired. I’ll cry.”
He grinned. “Wouldn’t want that.”
Behind them, the TARDIS lights warmed up even more, not merely gold, but something richer, and deeper.
Coda
They were still hovering above Ephyra-5, the planet a thin blue-grey crescent beneath them now, the red haze faded to memory, when the TARDIS settled back into her familiar, comfortable blue.
Donna had fallen asleep in the jump seat, head lolling sideways in absolute exhaustion. She snored once, turned over, then quieted again.
The Doctor watched her for a moment — soft and fond and exhausted right down to his bones.
He kept drifting around the console like he didn’t quite trust his legs, adjusting a lever here, tapping a dial there, frowning at nothing.
Donna cracked one eye open.
“You’re fussing.”
“I’m recalibrating.”
She snorted. “Same thing.”
He shrugged and wiggled his fingers near his temple. “Temporal sense… Most of it is solid again. It’s the futures that won’t quite behave. All those strange little what-ifs keep bleeding together.”
“You save the universe, nearly lose your ship, and you’re annoyed you’re not back at full clarity. Typical.” Donna replied.
He huffed a laugh. “It’ll settle. Eventually.”
A low, rhythmic chirring burst through the comms. Almost like a purr.
Donna sat up. “Did you hear that?”
The Doctor froze, hand hovering over a switch.
The sound came again through the speakers: a soft, rhythmic chirring, intimate as breath moving through warm soil. Not loud. Not urgent. Almost… thoughtful.
He adjusted a dial, and the sound thinned, separated, resolved itself into words.
“Next time…” there was a pause, long and wet with static, “…sit higher.”
Donna went absolutely still. “No,” she said flatly. “That was in my dream just now,” she said. “That exact sentence. And there was… well, something chased me. Something like … oh no – like that comfort-kin thing. But – bigger.”
The Doctor exhaled slowly.
“No, no, no. Doctor, tell me that is not the mushroom mafia phoning back.”
He frowned. “It’s not a signal.”
“It’s talking.”
“Yes, but,” He hesitated, choosing his words carefully. “It’s not thinking anymore.”
The whisper crackled again, softer now, already fraying at the edges.
“So how does something that’s dead remember my nightmare?” Donna asked.
“Because for a while,” he said, quietly, “You weren’t just hearing it. You were part of the same network.”
She looked at him.
“Donna… the Myrdaceps wasn’t just in the planet. Or the TARDIS. Or me.” He swallowed. “We formed a loop,” he said quietly. “Telepathic bleed-through. It left… impressions.”
She stared at the console. “So, it remembers… what, exactly?”
“Not memories,” he said gently. “Not properly. More like… fingerprints. Pressure marks.”
She grimaced. “Great. So, bits of fungus know my subconscious.”
He attempted a shrug. It came out lopsided. “Fragments. Fading ones.”
Donna chewed on that. Then her eyes widened. “Oh.”
“What?”
“Remember, one of their scientists got eaten,” she said quickly. “Proper horror story. Am I going to start dreaming about that now?”
He blinked. “…Possibly.”
“GOD NO.”
“I doubt it,” He laughed, “Look.” He pointed at the monitors. “It’s all dissipating. No active structure. No cohesion. Just static in the psychic ducts.”
And, true enough, the chirring softened, unravelled, collapsed into harmless noise, then silence.
The TARDIS lights softened, glowing gold around them in a warm, protective cocoon. Almost like she was tucking them in.
Donna exhaled slowly. “Right. Well. Let’s maybe avoid planets that talk back, yeah?”
He didn’t answer straight away. He rested his hand on the console instead, feeling the steady hum beneath his palm.
“Yeah,” he said at last, quietly.
She glanced at him, surprised.
He gave a small, tired smile. “Just for a bit.”
The TARDIS gave a low, contented hum, and the time rotor surged upward, bathing the room in blue-gold light.
The Doctor rested his hand on the console. “Ready when you are, old girl.”
And with a soft, affectionate whirr, the TARDIS vanished into the stars.
END