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The first thing Shouto noticed was the light.
A sharp, blinding beam slicing through the dense fog behind his eyes. Cold fingers pried open his left eyelid, stretching the skin until it burned. A click sounded nearby—some metallic device—and then a voice, clinical and detached:
"There it is. Subject 001 is conscious."
The fingers released him. His eyelid fluttered weakly closed. The light retreated, leaving a white afterimage burning against the inside of his skull.
He blinked, once, twice. Thick. Slow.
The ceiling above him was too bright, like staring directly into a sterile sun. His eyes watered uncontrollably, the tears leaking sideways into the crevice of his temple. He tried to move his hand to wipe them away, but a harsh tug at his wrist stopped him — metal cuffs around both wrists, both ankles, fixed to the edges of a narrow, cold table.
Panic should have come.
Instead, there was only a dull, sinking heaviness inside his chest. A familiar weight. The drugs hadn't worn off yet.
He knew this place. The too-bright lab. The stale, recycled air that tasted like metal and plastic. The stench of disinfectant that clung to the back of his throat. The table beneath him was cold enough to leech the warmth from his skin, even through the thin white hospital scrubs clinging to his frame.
The cuffs chafed, leaving pink, raw bands around his ankles and wrists. He barely registered them anymore. A shadow moved across his blurred vision.
"Vitals steady," a second voice said, female this time, sharper, impatient. "Sedative half-life extended. He won't be fighting."
Shouto's head lolled sideways. He tried to lift it, but his muscles didn’t listen. He could hear them, shifting around him — the doctors, the scientists — their footfalls crisp against the polished floor.
One of them leaned into view.
He was middle-aged, with short black hair and glasses perched low on his nose, wearing a spotless lab coat. A laminated badge clipped to his chest: Dr. Kurogane.
Kurogane smiled—an empty, joyless thing—as he scribbled something onto a clipboard.
"Good morning, Subject 001," he said, voice smooth, practiced. "Today, we'll be continuing our tolerance tests."
Shouto blinked again.
Subject 001.
The name stung somewhere deep inside him, like a splinter he couldn’t remove.
He knew there had been another name, once.
But he couldn't remember it.
Not anymore.
Another figure moved into view. Dr. Sato—young, eager, her brown hair twisted into a tight bun. She adjusted the strap securing his left arm and murmured absently,
"Poor thing. He looks thinner every day. We’ll have to supplement if we want him to survive the next battery."
Kurogane chuckled softly, the sound sliding over Shouto’s skin like oil.
"He’s durable. A product of...excellent conditioning, I suppose. Nature, nurture. We'll find out soon enough."
The way he said it made bile creep up Shouto’s throat.
Another tech, Matsuda, approached carrying a tray of instruments. Small syringes. Pressure clamps. Thermometers. Electrodes. Shouto's blurry gaze caught on the glint of a long, thin needle.
He couldn’t speak.
His throat wouldn't work.
Even if it did, he wasn't sure what he'd say.
Please.
Stop.
No. There were no pleas here. Only data points. Only measurements.
Matsuda strapped a sensor around his upper arm, tightening it until his fingers tingled.
"Starting at baseline," Matsuda reported. "Fire output first. Then ice."
Shouto tried to shift away when he felt the first sting of the needle—puncturing the inside of his elbow, sliding under his skin—but the restraints held him firmly in place.
A chill washed through his body as the IV line activated. Something cold, something burning. Adrenaline? Some quirk-enhancement drug?
The world tilted, swimming dangerously. His heart hammered painfully against his ribs.
"Heat output commencing," Dr. Sato said, tapping at a tablet.
A series of loud clanks echoed overhead. Metal panels slid away from the ceiling, revealing long black arms—machines equipped with heat sensors and thermal imaging cameras.
"Push the left side," Kurogane ordered, his voice dropping into the tone one might use with a disobedient animal. "Raise your body temperature by fifteen degrees, Subject 001. We’re monitoring internal tolerance thresholds."
There was a pause.
They waited.
Shouto lay still, blinking sluggishly. He couldn’t move. But then — his body reacted anyway. Instinct. Conditioned responses hammered into him long ago. The left half of his body—his fire—flickered to life.
A low, crackling warmth spilled from his skin. His fingers curled slightly against the restraints. The heat radiated outward, visible in shimmering waves to the cameras.
"Increase output," Sato prompted.
The heat increased. The warmth became uncomfortable. Sweat pooled at his hairline.
Shouto’s breathing grew shallow, ragged. His heart stuttered once—pain lancing up his side.
He wanted to stop.
He couldn't stop.
The monitors beeped sharply as his internal temperature rose.
"Core temperature exceeding normal parameters," Matsuda reported. "Warning signs for heatstroke at current rate."
Kurogane leaned closer, his shadow falling across Shouto’s dazed face.
"Remarkable, isn’t it?" he mused. "He doesn't even resist. Conditioned beyond fear. I wonder if it's the father’s doing, or simply necessity."
The word father sliced somewhere deep inside his skull, opening old wounds that still festered.
Before he could dwell, another order:
"Now ice," Sato snapped. "Switch."
The whiplash forced a hoarse, broken gasp from Shouto’s throat.
His right side — cold.
His left side — still burning.
His body rebelled violently against itself, muscles locking and twitching.
Frost began to crawl up his fingers, down his forearm. His breaths became visible in the frigid air, little puffs of white mist.
The pain wasn’t sharp. It was slow.
Creeping.
Devouring.
He felt the edges of his fingers first — the horrible numbness of impending frostbite. His vision tunneled.
"Monitor hypothermic onset," Kurogane said clinically.
Sato moved closer, examining the purplish tinge of his fingernails.
"Incredible resilience," she said, almost admiring. "He should have passed out already."
Shouto dimly felt the burning sensation in his left side — heat lingering under his skin even as the right side froze.
Two halves at war, tearing the body between them.
He closed his eyes.
Behind his eyelids, he saw a boy with green hair, laughing.
A hand reaching for him.
A taste of cold soba noodles.
A woman’s gentle voice calling, "Shouto."
The name slipped away like smoke.
A sharp slap across his frozen right cheek snapped his eyes open again.
Sato frowned at him.
"No losing consciousness yet," she said briskly. "Stay awake, 001."
He stared at her numbly.
Another set of footsteps echoed in the lab—heavier, deliberate.
Dr. Yanagi, the lead geneticist, approached, his silver hair shining under the lights.
"Prepare him for sampling," Yanagi commanded. "We’ll harvest marrow this time."
Matsuda hesitated.
"He’s barely stable—"
"Do it," Yanagi barked.
There was a flurry of motion.
Tools clattered.
Rubber gloves snapped.
Something cold and metallic pressed against Shouto’s hip. He recognized it, distantly—the surgical drill.
He wanted to scream.
He couldn't.
The sedation had stolen even that.
The drill whirred to life.
Pain bloomed, white-hot, blinding.
His body spasmed against the restraints, the cuffs biting into his wrists hard enough to split the skin. Warm blood trickled down his arms.
Still, no sound escaped him.
The world fractured into pieces—white light, cold metal, red pain, numbers, needles—
"Subject 001 is responding well," Kurogane said distantly. "No shock. No cardiac arrhythmia."
They sounded pleased.
Through the roaring in his ears, Shouto caught scraps of conversation:
"Harvest cells from the spinal tap next session."
"Prepare hybridization vats. We’ll attempt fusion with Subject 014 and 017."
"New subjects arriving from the outer wards tomorrow. Quirk donors prepped."
New subjects.
Like him.
Pieces for them to cut and stitch into something new.
Maybe once, he would have fought.
Maybe once, he would have believed someone was coming.
Now... there was only this.
The light.
The table.
The name "Subject 001."
He closed his eyes again.
Let the pain consume him.
And waited for the next test.
The restraints released with a sharp, metallic click.
Shouto barely registered the sudden freedom. His limbs sagged uselessly, dead weight after hours—or was it days?—of being pinned down.
Rough hands seized him under the arms.
"Lift him. He's not moving," someone grunted.
He was yanked upright with a jolt that sent sharp, electric pain shooting through his lower back and shoulders. His legs buckled immediately, trembling under his own weight.
The two orderlies—he recognized them vaguely through the drug-haze: Hirose, the taller one with buzzed hair, and Abe, stockier with a jagged scar along his jaw—grunted as they half-dragged, half-carried him off the metal table.
His bare feet scraped against the freezing floor.
The chill seeped straight up into his bones.
"Tch. Pathetic," Hirose muttered, adjusting his grip when Shouto’s knees buckled again. "They call him the masterpiece?"
"Doesn't look like much now," Abe snorted. "Just another half-dead freak."
The lab door hissed open.
Blinding white light spilled into a long corridor lined with cylindrical glass tanks—the vats.
Shouto’s heart gave a weak, fluttering thud against his ribs.
He had seen them before.
He had been inside them before.
The tanks stretched down the hall like monstrous coffins, each one connected to thick black cables and shining with condensation. Most were occupied: distorted shapes floating inside, some still, some twitching. Faces blurred by glass and fluid.
Some he recognized, in a vague, hollow way.
The girl with electric blue veins spiderwebbing across her skin.
The boy whose arms had fused into long, fin-like appendages.
Experiments.
Subjects.
Like him.
"Move it," Hirose growled, jerking Shouto forward roughly.
His body swung forward like a ragdoll, head lolling against Hirose's chest.
At the far end of the hallway stood his tank.
Empty. Waiting.
The glass door gaped open like a mouth ready to swallow him whole.
Abe tapped at a small panel on the side, inputting a code. Lights blinked green.
Together, they maneuvered Shouto inside.
The interior was brutally cold.
He stumbled against the smooth glass wall before the restraints snapped into place—thick padded bands around his wrists, ankles, chest, pinning him upright against the back panel.
The weight of his body sagged against the restraints, sending stabbing aches into his shoulders and thighs. His breath fogged against the glass in shallow bursts.
"Strap his head," Abe reminded.
Hirose pulled a wide strap across Shouto’s forehead, fastening it to the metal frame behind him. His neck jerked slightly under the pressure, head forcibly held upright.
Then came the worst part.
Hirose slipped on sterile gloves and reached for a small, hideous-looking device on a nearby tray: the oxygen-feeding mask.
Shouto’s sluggish mind recoiled instinctively, dread prickling along his spine.
He opened his mouth to protest—to do something—but his jaw just hung slack, muscles too slow, too heavy.
Without hesitation, Hirose inserted the gag extension inside Shouto’s mouth—a thick, rubberized piece that forced his mouth wide open, locking his tongue down, stretching his jaw uncomfortably.
Shouto gagged weakly as the gag filled his mouth, the edges pressing against the back of his throat, the urge to retch crawling up his chest.
"Hold still," Hirose muttered, annoyed, as he tightened the mask over Shouto’s face.
It sealed completely around his nose and mouth, hissing softly as it activated. A long tube trailed from the front, connecting him to a larger machine on the wall: air supply, feeding line, monitors.
The gag prevented him from swallowing properly.
Saliva pooled uncontrollably at the back of his throat, sliding down in thick, slow drips he couldn’t control.
The mask was tied tight behind his head, straps digging into his scalp.
Abe stepped forward, pressing sticky pads against Shouto’s forehead, temple, and chest under the loose white scrubs.
They itched immediately, clinging to his chilled, damp skin.
"Telemetry active," Abe confirmed. "Neural readings stable."
Outside the glass, Hirose consulted a clipboard.
"Load compound B-07 into the filtration system," he ordered casually. "He’s overdue for full sedation."
"Acknowledged," replied a robotic female voice from the intercom.
There was a clunk as the chemical feed engaged.
Through the fog of discomfort, Shouto knew what came next.
The tank door swung closed with a soft, final thunk.
Locks engaged.
He was sealed inside.
There was a brief, humming vibration—and then the chilling rush of water began.
It poured from hidden vents above him, icy and relentless.
First around his feet and ankles, swirling cold against his skin.
Then rising up his calves, thighs, waist.
He could feel the water saturating the thin fabric of his scrubs, dragging them down, plastering them to his skin.
Higher.
His heart thudded weakly in his chest, every beat sounding muffled by the rising liquid.
The water reached his chest, sloshing against the oxygen mask. His arms twitched helplessly against the restraints.
He hated this part.
He hated the pressure.
The unnatural stillness they forced on him.
The water climbed to his shoulders. His neck. His chin.
He squeezed his eyes shut as it closed over his head entirely.
The mask hissed gently, supplying oxygen and nutrients.
He could still breathe—but each breath felt wrong. Heavy. Artificial.
The cold bit into him relentlessly, gnawing at muscle and bone.
Designed to push him as close to hypothermia as possible without killing him.
Through the distortion of the water and glass, he could still see the blurry outlines of Hirose and Abe outside the tank.
They stood there casually, tapping at screens, inputting commands.
"Initiate sedative compound flow," Hirose said. "Cycle duration: seventy-two hours."
Abe nodded.
"Sedative B-07 and mild paralytic administered. He won't move."
Shouto felt the new chemical slip into his bloodstream through the IV lines taped to his arms.
It was different from the earlier sedation.
Heavier.
Darker.
His mind began to slow, the world tilting lazily, sinking deeper and deeper into a numb, heavy silence.
The outlines of the lab techs outside blurred further.
He saw Hirose grin, a flash of teeth, distorted by the water.
"Sleep tight, Subject 001."
The overhead lights dimmed slightly, a pale, blue glow filling the hallway.
Time stretched thin, pulled apart like taffy.
Shouto's thoughts floated loose from their moorings.
Somewhere in the farthest corner of his mind, a tiny ember of self stirred.
A whisper.
A memory of another life.
Of laughter. Of hands reaching for him. Of someone shouting his name—
Shouto.
—but the drugs were stronger.
The cold was stronger.
The tank was everything.
His eyelids drooped, his body sagging further into the restraints.
The last thing he saw, before the dark swallowed him completely, was Hirose walking away without a second glance.
As if he were nothing more than another lab sample.
As if he weren’t even alive at all.
And then, there was only the cold.
And the dark.