For the first time in three days, Chen Mo opened his door.
Heavy breaths rasped through the filter canister of his gas mask. Sweat in his palms had already soaked the grip of the fire axe.
The corridor reeked of a sickly-sweet rot—like meat soup left to boil under the summer sun, so thick and pungent it seemed to cling to the lungs.
His combat boots thudded dully against the damp carpet.
The pool of blood that had once seeped under his door had long since dried to a dark, amber-like crust—yet its edges still caught the light with an unsettling sheen, as if ready to flow again at any moment.
On the seventeenth-floor landing lay half a corpse.
Chen Mo raised the axe in both hands and recognized him—Old Wang from next door, an orthopedic surgeon before retirement. Now his left arm was bent backwards at an impossible angle, bone punching through skin like a pale spear.
More disturbing still were the milky eyes fixed unblinking on the ceiling—where a pink dress hung from the chandelier by twisted wire. It was his granddaughter's favorite.
Hhhhhh—
Old Wang's throat wheezed like a broken bellows, his chest heaving violently without a single breath passing through. Ribs jutted under skin like the jagged bars of a cage.
Chen Mo's grip slipped slightly—three years ago in the dissection room, he'd seen bodies seized in postmortem spasms from rabies infection. But never one that held its posture as if still alive.
Lin Lan had once said: A virus's ultimate goal isn't to kill its host—it's to remake it, turning it into a more efficient tool for spread.
Old Wang suddenly folded at the knees to a perfect right angle, head nearly touching the floor. His nose brushed a bloodstain on the carpet, leaving a faint red arc as he slowly inched toward Chen Mo.
The axe came down, cleaving the skull.
The reek of formalin hit him—dense, chemical, cloying with the sweetness of brain matter—like a bottle of cheap perfume smashed on the floor.
Pinning the convulsing leg under his boot, Chen Mo noticed a tiny puncture at the back of the man's neck, its edges bruised dark blue. The mark was identical to the injection points on experimental subjects.
"You too… a test subject?"
His murmur echoed in the hollow stairwell.
In his memory, Old Wang had once laughed, showing off his granddaughter's awards. Now all that was left was this mess of blood.
Footsteps pounded from the fifteenth floor—heavy, urgent.
A security door banged open from inside, and a woman in pajamas stumbled out, clutching a swaddled bundle.
The sound from the bundle wasn't crying—
it was the clear, hard click of glass beads colliding.
"My baby is hungry…"
Her clouded eyes softened into a tender smile.
"He wants something fresh… look, isn't he adorable…"
Chen Mo froze mid-swing—
because the "baby" wasn't a baby at all,
but a writhing mass of flesh-colored tissue, its surface studded with countless tiny eyes. Each iris reflected his image,
like a thousand warped mirrors staring back.
Lin Lan's research had described such "aggregate organisms"—virus-triggered monstrosities reshaped within the womb.
The woman suddenly thrust the bundle toward him, nails biting deep into his arm.
"Help me… he's just hungry… just one bite…"
The axe fell.
The clean crack of metal through bone rang out, and for a moment Chen Mo thought he heard gunfire again—
the gunfire on the border three years ago,
and the last wheezing breaths of the child struck by a stray bullet in his arms.
At the twelfth-floor corner, a scream tore the air—it was Su Xiaoxiao.
Her fruit knife was pressed to the throat of a middle-aged man—Mr. Zhang from 1203, her former physics teacher.
Half his face had rotted away, muscle fibers squirming in the open, yet he still clutched a Physics Experiment Manual.
On its cover, scrawled in red ink:
"Light travels in straight lines, so shadows never lie."
"He tried to steal my first aid kit!"
Su Xiaoxiao's hand trembled, the blade smeared with pale green slime.
Mr. Zhang chuckled low in his throat.
"Shadow… your shadow is moving… it's trying to escape…"
Chen Mo glanced down—Su Xiaoxiao's shadow was faintly warping, while at Zhang's feet there was nothing at all.
Lin Lan's notes came to mind:
Deeply infected hosts can bend light—see what cannot be seen in darkness.
"Turn on the UV lamp!" Chen Mo chopped at Zhang's wrist. "Light kills them!"
Under the glare, Zhang screamed. His skin bubbled and smoked like melting wax, revealing veins black-blue beneath.
Worse—the shadow behind him condensed into a vague human shape and bolted.
"Shadows are the virus's core carriers!" Su Xiaoxiao's voice broke in panic.
They fled down the stairs.
From the open doorways, shadow-creatures slithered in silence—
some manipulating objects: at the entrance to 302, a piano played Für Elise on its own,
its bloodstained keys blooming like red poppies.
"Go! This place won't hold!" Chen Mo barked.
Two hours of scavenging later, Chen Mo had found a Type 92 pistol with three rounds—the "just in case" parting gift from his old commander.
Su Xiaoxiao dug up a first aid kit and a solar radio.
She tuned to a certain frequency; faint, broken music floated through.
"My dad always said, in the apocalypse, medicine's worth more than food." She hesitated.
"And… he told me never to believe it when they say, 'It's just the flu.'"
Outside, in the garden, a dozen shadowed figures hunched among the bushes, white smoke rising where sunlight touched their skin.
They moved slowly but with precision, always finding the shade—like vampires fleeing the light.
Chen Mo remembered the strange text:
They're feeding on their own shadows.
Maybe, he thought, it wasn't sunlight they feared—
but the truth the light revealed.
From behind the ninth-floor security door came a knock—three short, three long, three short. The standard SOS.
The UV lamp revealed a human-shaped shadow inside, holding a smaller shadow in its arms.
"There's someone alive!" Su Xiaoxiao cried, reaching out.
Chen Mo stopped her—there was fresh, fluorescent green blood on the handle, the same color as Zhang's slime.
"Shadows can mimic human form."
The voice inside grew desperate.
"Help my child! I'm Nurse Li from 301!"
Su Xiaoxiao froze—Nurse Li was her mother's colleague, had even dined at their home last year.
"My dad's notes mentioned her—type E blood, resistant to the virus!"
The axe smashed the lock.
Inside, Nurse Li slumped on the floor, holding a rigid infant corpse.
The child's skin was marble-gray, eyes gouged out, the sockets yawning black.
"He won't drink milk…"
Her voice was vacant as she tilted a bottle of dark red liquid into the child's mouth—labeled AE blood type, the same as Su Xiaoxiao's mother.
"Run… they're in the shadows…"
She hurled the bottle at the wall; the spilled blood formed a strange barrier in the sunlight.
Before she could finish speaking, her body twisted violently, bones cracking like firecrackers,
her hands plunging into her own eyes.
Chen Mo yanked Su Xiaoxiao away.
The UV beam stretched a long bar of light on the floor, illuminating their shadows—
Su Xiaoxiao's edges quivered faintly, while his own was razor-sharp.
"My shadow… is it infected too?" she choked.
He remembered the text:
Keep your shadow sharp—that's the only proof you're uninfected.
Downstairs, in a wrecked sedan, a policeman tore into the passenger's neck,
while his shadow slithered toward the stairwell like a black snake.
"Hurry—to the basement! No windows there!"
The iron door was rusted, the keyhole clogged with sand.
Three swings of the axe, and the gap spewed swarms of shadows, scattering like startled bats.
"Turn the light to max!" Chen Mo braced the door.
Under UV glare, the shadows sizzled into smoke.
"There's a generator!" Su Xiaoxiao shouted.
Outside, the pounding was like elephants charging.
"Start it!" Chen Mo roared. "The noise will mess with the shadows!"
The generator thundered to life; its vibrations weakened, but the howls outside receded.
In the corner, a limping cat padded over, dropping a key in its mouth—engraved Underground Garage.
Its shadow was sharp and whole.
Chen Mo ran a thumb over the cold metal.
For the first time, a flicker of hope stirred in his chest.