The weight of the Glock 19 pressed against Shi-hun's lower back, the cold steel tucked firmly into the waistband of his jeans. It was a heavy, dense promise of power, contrasting sharply with the hollow exhaustion gnawing deep into his bones.
Room 612 was eerily silent, broken only by Yu-jin's ragged, intermittent breaths and the dripping of black blood from the shattered skull of the security guard's corpse. The file—Project Pandora—was safely stowed in Shi-hun's backpack. Ground Zero, this university wasn't just a victim. It was the womb that birthed this nightmare.
"We can't go down the stairs anymore," Shi-hun said, shattering the oppressive silence. His voice was flat, betraying no trace of the phantom pain still pulsing at the edges of his nerves from the clone's death. "The professors have fortified the main staircase on this floor. The fire escape is collapsed too. We have to drop straight down."
Yu-jin leaned her heavy body against a metal pipe, her face pale, bruises around her ribs stark against her skin. "The elevator shaft," she realized, her voice trembling. "But there's no power..."
"We'll rappel down the cables."
Her eyes widened, snapping to the void outside the window they'd just escaped from. "Shi-hun, look at me. I'm wrapped in foam casts and can barely stand. My ribs are cracked. I can't support my own weight on those greasy cables for six floors. I'll fall for sure."
He had created a clone just moments ago, only to leave it to be torn apart. The unspoken thought hung heavy between them. She knew that if she fell, he couldn't catch her. He was just human. He didn't have the monstrous strength to stop a plummeting body with one arm.
Shi-hun stared at her, cold calculations racing through his mind. She was right. One slip meant death, and sacrificing lifespan to create another clone mid-air to catch her was too risky. It required perfect timing—too perfect.
He opened the system interface.
[Remaining Lifespan: 198 days]
He needed tools. His eyes scanned Room 612 before stopping on the corpse of the former security guard he'd just killed. Strapped to its chest and waist was tactical webbing and a thick nylon belt for rappelling. It was made of tough, durable material, and most importantly... it had high-tensile steel carabiners attached.
He approached, kneeling beside the blood-soaked body, and unbuckled the strap. But there was only one set, and it was stained with thick black blood. He needed another perfect one for Yu-jin's safety. He touched the original strap and focused.
[Duplicate? Target: Nylon Tactical Webbing with Steel Hooks. Complexity: Medium. Cost: 2 days. Yes/No]
He confirmed. A blue light flashed in the dim room. A brand-new identical strap—clean of blood and rot—appeared in his other hand. [Remaining Lifespan: 196 days]
He tossed the newly duplicated clean strap to her. "Wrap it around your chest, over the casts. Lock the steel hook onto the main cable. It'll act as a safety harness. If your hands slip, this will hold you. You won't fall."
Yu-jin stared at the pristine nylon webbing, then at his face. The utility of his power was terrifying. She looped it around her torso. The metal mechanism clicked securely. "What about you?"
He picked up the original bloodstained strap from the guard and wrapped it around his own waist. "I'm not planning to slip. Move."
***
They used a metal table leg to pry open the elevator doors on the sixth floor. The shaft yawned wide in welcome—pitch black, reeking of rust, stagnant water, and the metallic tang of old blood. A draft howled up from the unseen bottom, wailing mournfully through the cables.
Shi-hun went first. He gripped the thick braided steel cable, slick with industrial grease, cold and viscous. He clipped the carabiner onto the line and lowered himself into the void. His feet braced against the concrete walls of the shaft to control the descent. The darkness swallowed him from the waist down.
Yu-jin followed. She hooked her carabiner onto the cable. The steel locked with a reassuring crack. She swung over the edge.
Pain ignited immediately. Her cracked ribs ground together as gravity pulled at her body. She hissed, a sharp sound of agony escaping uncontrollably. But the safety harness bore her weight, easing the potentially fatal strain on her arms.
"Climb down, alternate hands one at a time," Shi-hun's voice echoed from the darkness below, calm and methodical.
They descended. The shaft amplified every sound: rubber soles scraping concrete, the overhead cable brackets creaking ominously, their own erratic heartbeats. The air grew colder, heavier, laced with rot from the lower levels.
Ten feet. Twenty. Thirty.
At the fourth floor, Yu-jin's left boot slipped on a thick smear of grease on the wall. Her hands lost their grip. She dropped.
But only a foot. The nylon harness jerked taut with a violent thwack. The carabiner locked onto a knotty glob of grease on the cable. Her body slammed into the wall. She screamed as her ribs took the blunt impact. But it held her. She lived.
Shi-hun paused below her, shining his flashlight up. The beam cut through the dust. "Breathe. Grab again. Keep climbing." No panic, no comfort—just the mission.
She gritted her teeth, tears of pain welling up, and pulled herself back to brace against the wall. The harness had saved her, but this descent was draining her last reserves of strength.
Faded yellow floor numbers passed: 4... 3... 2. "Stop," Shi-hun commanded.
Below them, the shaft was completely blocked. The elevator car was jammed between the first and second floors, its roof caved in. The cables above were tangled in a massive, twisted knot of metal—impassable. They couldn't descend straight to the basement through the shaft.
"We have to exit at the second floor," Shi-hun said, kicking at the doors on the second-floor landing. They budged slightly. He wedged his boot into the gap and pried. Metal screamed, opening just wide enough for them to squeeze through.
They rolled out onto the second-floor landing. Yu-jin collapsed against the wall, unclipping her carabiner with shaking, bloodied hands. Her chest heaved, face chalk-white with exhaustion.
Shi-hun drew his duplicated kitchen knife, sweeping the flashlight beam down the hallway.
The second floor felt utterly warped.
***
The air was dank and thick with dust and a sharp, metallic tang that clawed at the nostrils—like rusted surgical tools left in acid rain. Emergency lights flickered in a sickly yellow, on the verge of failing.
Shi-hun led, Yu-jin trailing behind, using the metal pipe as a crutch. They had to navigate to the stairwell to bypass the jammed elevator and reach the basement.
Shi-hun pushed open a side lounge door—once a student break room, now a snapshot of a slaughterhouse. An overturned vending machine formed a makeshift barricade. Shattered glass glittered on blood-soaked carpet. The inner door was heavily barricaded from inside with stacked chairs and metal filing cabinets. Someone's last stand.
"This happened recently," Shi-hun muttered.
He dragged a finger over the wood. The scratches on the barricade were fresh. Dark blood smears streaked the floor, but they didn't lead to the door. They trailed straight to a large air vent near the ceiling. Its heavy steel grate had been completely ripped from the wall, edges bent outward with raw, savage force.
Yu-jin poked at a pile of debris in the corner with her pipe. Shredded clothes and bones.
Human bones, gnawed clean.
This wasn't standard zombie work. The tooth marks etched deep into the femur were too orderly and razor-sharp. The bone had been snapped horizontally to suck out the marrow. A small pink shoe lay nearby—child-sized. Above, scrawled in panicked blood: "They come from below. Don't open the vents."
The environmental wounds told a brutal truth. Bullet holes riddled the walls—heavy firepower defense. Blood splatters arced high toward the ceiling. The attackers hadn't breached the door. They'd dropped from above. Whatever did this was fast, agile, and terrifyingly powerful.
A low growl rumbled, echoing from the ceiling ducts.
They froze.
Scratch. Scratch.
From the torn vent, a nightmare crawled out like a giant mutated insect. It hit the floor with a wet, sickening crunch of malformed bones. It had been a former student, but the virus had twisted its form. Limbs elongated unnaturally, skin stretched taut over extra-jointed bones. Its jaw hung slack, lined with needle-like teeth. A "Jumper"—evolution born in darkness.
It didn't shamble. It leaped.
It crossed the distance with horrifying spider-like speed. Yu-jin reacted on pure adrenaline, swinging her pipe. Metal connected mid-air with a nauseating crunch, shattering the monster's arm bone. But the Jumper landed perfectly, unfazed, lunging at her legs.
Shi-hun stepped in. He couldn't overpower it with brute strength, so he used momentum. As the creature pounced, he dropped to one knee, angling the kitchen knife upward. The mutant impaled itself on the blade. Its own kinetic energy drove the steel deep through its throat and into the brain stem.
Black viscous blood sprayed across Shi-hun's face. He twisted the hilt and yanked it free as the body slumped.
[Kill Confirmed. +1 day. Remaining Lifespan: 197 days]
But the rumbling above intensified. Two more dropped from the vent.
"Door," Shi-hun barked.
Yu-jin didn't hesitate. She backed into the hallway. Shi-hun hurled a heavy chair at the nearest Jumper, tangling its elongated legs. He retreated from the room, slamming the thick wooden door shut just as one body slammed into it from inside.
He gripped the outer handle, holding it fast. "Find something to wedge it."
Yu-jin dragged a nearby trash bin and jammed it under the handle. Wood splintered under the frenzied pounding from within, but it held.
"They're evolving," Yu-jin gasped, staring at the buckling door. "The ones upstairs were slow, but these..."
"The virus adapts to the environment," Shi-hun said, wiping black blood from his eyes. He recalled notes from Project Pandora. "Confined spaces, hunting in darkness. It modifies their bone structures."
He glanced down the hallway toward the main stairwell. The path to the basement.
"We're going down," he ordered.
***
They reached the heavy metal fire door leading to the first floor and basement. It was heavily dented from the inside, as if a desperate crowd had battered it to escape the stairwell.
Shi-hun paused, placing a hand on the cold steel. He opened the interface.
[Scan: Hostile Detection] A blue overlay flickered across his vision. Zombies clustered densely on the first floor beyond the door—dozens. But they weren't attacking the barrier. They pressed against the opposite wall, backs to the stairs descending to the basement.
He monitored their vitals. Heart rates—for those that still had pulses—spiked wildly.
Fear. From the undead. A biological paradox.
"They're terrified," he whispered. "Fleeing from the basement path."
Yu-jin gripped her pipe with both hands, knuckles white. "Fleeing from what?"
Shi-hun didn't answer. They bypassed the first floor entirely, descending the final stairwell into the dim underground.
The emergency lights here didn't flicker yellow. They hummed in a sharp, blood-red glare. Temperature plummeted instantly, freezer-cold, turning Yu-jin's breaths into white mist. Concrete steps were slick with congealed blood, frozen into deadly crystalline flakes.
Deeper down, the walls were scarred. Massive gouges in the concrete, deeper than any human nails could carve. Large chunks of masonry missing entirely, as if bitten away by jaws the size of car tires.
The stairwell acoustics amplified every faint noise: drip, drip, rhythmic.
And beneath it all—a pulse.
Thump... Thump... Low, drawn-out, vibrating through their boot soles. It sounded exactly like a heartbeat—an impossibly massive heartbeat echoing from B3.
They reached the B1 landing. The reinforced steel door was slightly ajar. Shi-hun pushed it open. Hinges screamed in the silence.
The B1 hallway stretched into perfect darkness. Red flashes cast long, twisted shadows dancing on the walls. Overhead pipes were frost-encrusted, icicles frozen mid-drip into sharp stalactites.
They advanced slowly. Shi-hun with knife in left hand, right resting lightly on the Glock 19's grip. Maximum noise discipline.
Suddenly, something stirred ahead in the corridor. The darkness peeled away to form a silhouetted bulk blocking the way. A resonant growl echoed—impossibly deep, shaking the air.
A zombie dog.
But not just any dog. A former police K9, tactical harness and collar still strapped to its thick neck. A metal tag faintly read "Seoul PD." It had mutated horrifically. Fur patchy, exposing gray armored skin beneath like petrified bone. Spine and ribs protruded like jagged thorns. Eyes glowed crimson with feral rage. Its jaws unhinged grotesquely wide, beyond biological limits, revealing serrated shark-like teeth.
It crouched low to the ground. Acidic saliva dripped viscous from its maw, hissing softly as it corroded small pits in the concrete.
Thump... Thump... The massive heartbeat below swelled in response—shaking walls violently, dislodging ice from the ceiling like snowfall.
Then, other shapes emerged from the dimness.
Two. Four. Six.
Crimson eyes locked on them from the gloom. A pack of wolves.
Before Shi-hun could draw his Glock, a mechanical slam echoed from behind: Bang.
The reinforced steel door to the stairwell swung shut, triggered by automatic lockdown protocol. Heavy pneumatic locks engaged with a resounding, final click.
Trapped. Locked in B1's frozen chamber, with the mutated K9 pack ahead, and the massive heartbeat awaiting below.