Prologue: Beyond the Iron Gate
In that fleeting instant she crossed the threshold, an ominous sensation slammed through her entire body — as if the physical laws and order of the world itself had twisted into something grotesque.
Outside the old iron school gate, the sticky, sweltering humidity of late summer had pressed heavily against her skin. Every breath had filled her lungs with lukewarm, murky air — an utterly ordinary, thoroughly unpleasant tropical night.
But the moment she stepped across the boundary line into the school grounds, every trace of that seasonal weight clinging to her skin evaporated in an instant, as if it had all been a lie.
A chill.
It was not a simple drop in temperature. A bone-deep, marrow-freezing cold — the kind that seemed to steal the warmth from the blood in her veins — crept up from her ankles in a slow, crawling crawl. A spiritual frost, as if the icy breath of the dead were brushing directly against bare flesh.
A nauseating tinnitus bored into her ears, as though both eardrums had been packed tight with thick wads of cotton.
Beeeee—
It was not merely the severing of sound. The wind that had been tousling her hair from behind cut off as abruptly as if it had struck a physical barrier. The flow of air around her stopped dead, and a strange atmospheric texture scraped roughly across every inch of her skin.
The faint friction of car tires on the mountain road far below, the chirping of insects — all of it was sealed away as though a massive soundproof wall had dropped over everything.
With every breath, a peculiar stench stabbed sharply at her nostrils and pushed deep into her lungs. It was something like the mildew of old books rotting damply in a basement corner that had never once seen sunlight — or like the metallic, nauseating reek of rusted iron that rises into the air when dark blood hardens and congeals.
Her stomach twisted with revulsion. She swallowed dryly.
"Wh…?"
A parched sound slipped past her lips. Even her own voice rang dull and thick, as if spoken underwater.
She roughly wiped the cold sweat from her forehead with her sleeve, then pulled her smartphone from her pocket with trembling fingers. The pale, bluish light of the screen washed over her rigid face.
The time was exactly midnight. 00:00.
Worse than the primal unease of those digital digits was the symbol floating in the upper-right corner of the screen. The antenna bars that had been full just moments ago, when she was still on the phone with her younger sibling, had been replaced by a sharp, unmistakable X.
No signal.
The cold mark of a complete break from the world — a declaration that the moment she entered the school, she had left the service area entirely.
Tap. Tap!
She dragged her shaking thumb down the screen again and again, hammering the refresh button, but the antenna kept circling empty air, catching not even the faintest frequency.
Her pupils trembled as if shaken by an earthquake. Her bloodless fingertips accelerated their meaningless tapping.
It's just because this is deep in the mountains. The signal doesn't reach here.
This is a remote foothill, far from the city.
With terrain this closed off, of course the cell towers can't get through. It's a perfectly normal physical phenomenon.
She fought desperately to drag this abnormal situation back into the realm of rational explanation. If she didn't, she felt she would scream and bolt out through the gate like a wild animal right then and there.
She drew a deep, chest-crushing breath and forced the dead lump of scrap metal that was her phone back into her pocket.
When she lifted her gaze, the main building of the Old Building emerged from the dense ash-gray darkness.
Crunch. Crunch.
She forced her legs — heavy as if glued to the ground — to move, stepping onto the gravel path. The sharp stones crushing and grinding underfoot tore through the night air with an unnaturally loud, skin-crawling sound.
Every nerve strained toward that noise as she walked toward the only light in the darkness — the Security Office. And behind her, she never once noticed that the massive iron school gate, which had stood wide open, had begun to move on its own.
Like a spider slowly sealing the entrance to trap prey that had walked in on its own legs, the gate closed with no friction, no sound — slow and secretive. But the stiff back of her head, locked in extreme tension and staring only forward, had no eyes.
In front of the old Security Office door, damp sweat soaked the palm gripping the rusted aluminum handle.
She opened the door and stepped inside. Stale air filled her vision, and with it, a figure waiting for the shift handover.
Overhead, a fluorescent light near the end of its life flickered with a neurotic buzz. Beneath it, a single old, grime-caked fan rattled violently as it spun, churning the musty air of the Security Office with forced, clumsy effort.
"Tsk. I know finding people for this job is like plucking stars from the sky, but still — sending a young girl like you to a godforsaken mountain hollow like this? What are they thinking?"
An elderly man sweeping odds and ends from the desk into his bag turned his head and looked her up and down, clicking his tongue without the slightest pretense of subtlety. Wariness and pity mixed strangely in the creases of his brow.
The narrow space was thick with the smell of old age seeping from the man's body, the reek of entrenched mildew, and the cloying sweetness of cheap instant coffee dried onto the floor — all of it tangled together, sticky and unpleasant in her nose.
"Don't worry about me. I may not look it, but I've got a martial arts certificate. I'm more confident in a physical fight than most men."
She forced the corners of her mouth as high as they would go and offered a bright-eyed smile. It was so artificial her lip muscles nearly spasmed — but when she thought of the enormous contract payment that would hit her bank account, even this unpleasant meddling and those staring eyes could be brushed off like feathers.
Besides, the claim that she had natural grit and could handle herself in a fight wasn't entirely a lie.
The man still shook his head, unable to erase the uneasy, reluctant look from his face.
Outwardly she put on a calm front of bravado, but the right hand shoved deep into her coat pocket was soaking through with even more cold sweat than before. Her pale, faintly trembling fingertips were clutching — desperately, hard enough to tear skin — a handful of talismans drawn crudely with a red marker, because she couldn't afford professional calligraphy ink.
In modern society, it was rare, but there were still ghosts that clung to people. The ones that merely latched on would scatter if you just waved something at them, and people would thank you as if you'd worked a miracle for simply going through the motions of driving them off. Some had already been to skilled shamans or monks with no effect. Others came grasping at straws. She had suffered for it, but she had fixed a few of them.
She needed that blind, desperate faith now — that those meager, pathetic past successes would somehow still hold against the terrible, vast energy of this pocket dimension. That the ones who had come to this school before her, for all their reputed skill, had simply been incompetents who fled in fear. That she could handle it.
Because if even this failed, there would be no way to survive the low-grade evil spirits and monsters waiting here.
Her grip inside the pocket tightened until the skin threatened to split, veins standing out. She rolled her shoulders — stiff with extreme tension — and adjusted the frayed strap of the canvas bag on her back.
Clink. Clatter.
Every slight shift of the strap sent a dull, unpleasant jangle rattling against her ear. It was the sound of an old brass bell bracelet hanging crudely from one corner of the bag like some trendy metal keychain.
It should have been a sacred shamanic tool, ringing with clear, luminous tones to drive impure things in every direction. But the brass had long since rusted a dark, murky red, its original golden light lost forever. Several of the bells had been torn off or broken, leaving it looking as grotesque as the mouth of a toothless beast.
Whenever terror made her body tremble beyond control, this old bell rang of its own accord with that dull clatter. If a situation ever came where silence was survival, it would become a fatal shackle — advertising her position to every enemy in the dark.
And yet she couldn't bring herself to tear off this piece of junk and leave it behind. Without even these garbage tools at her side, her mind could not endure the extreme terror of being thrown naked into the middle of hell.
One last remaining comfort.
With every shallow breath in and out, a cool, heavy metallic pressure settled against the soft skin beneath her underclothes — right at the pit of her stomach. A small ritual shaman knife, so badly rusted its blade had gone completely blunt.
It was nothing more than a scrap of metal too dull to peel fruit, too dull even to cut a single thin sheet of paper. But the cool metal sensation biting into her flesh with every breath was the only anchor still barely holding her reason in place.
A crude red marker. Talismans. A toothless old bell. A shaman knife reduced to blunt scrap iron.
The Poor Shaman's 3-Piece Set — so pathetic and wretched it made her face burn just to call herself a shaman.
Walking into a death trap with her life entrusted to tools this shoddy — the thought of herself doing it suddenly felt distant and unreal.
Five million won. Just the advance is five million won in cash.
The residual image of the numbers she had seen in her banking app crushed the spiritual revulsion and survival instinct screaming alarms in her head with sheer violent force.
Hang on in this eerie place, go through the motions of chasing off a few stray ghosts, and the daily pay was two hundred thousand won. On top of that, they were throwing in regular part-time hourly wages. Was protecting face and image really worth spending that much money? Once they sold off the school grounds for a fortune, the sum they'd given her would be nothing at all.
A few days' work equaled a full month of a regular salary. Clear it out fast, stand night security for a few more days, and it was basically printing money. And the unconditional advance already deposited — five million won. A miraculous number of salvation that could, in a single breath, wipe away her mother's overdue hospital bills and the sigh-inducing cost of medicine, her younger sibling's winter special lecture academy fees, and the rent demand notices plastered all over their front door.
It's a profitable deal. No matter what it takes — I have to do this.
She bit down on the inside of her lip hard enough to taste the metallic tang of blood, forcibly gripping her sense of self. Behind the bright, boastful expression flaunting her martial arts certificate, she locked her wrist tendons tight enough to ache, trying to stop the tremor in the pale fingertips hidden in her pocket.
"Well, if you're that confident, I guess there's nothing I can do. You're a grown adult — you'll figure it out. Still, lock the doors tight at night and take care of yourself. Lately we've had some crazy delinquents sneaking into empty schools after dark."
The man yanked the zipper of his bag shut with a rough pull as he delivered the warning.
"It's not even a closed school, but they climb all the way up here for some kind of courage test, or so they say…"
The eyebrows holding her smile twitched — just slightly, at a speed she couldn't control.
"Not long ago, a few students even went missing here. That's why the night patrols are this strict. You've got to check carefully whether any kids are still hanging around after dark, whether any weird outsiders are lurking."
The impact hit like a hard blow to the head. The muscles at the corners of her mouth, which she had been forcing upward, locked stiff.
They built a school on a foothill this remote, and people still come in at night?
It was a bizarre site condition that defied every category of common sense. A private high school of red brick, sitting alone on what felt like a sheer cliff, reachable only after a long climb up a winding mountain road with no streetlights. Unwelcome visitors using courage tests as an excuse. Students who had vanished without a trace.
The logic circuits in her head spun furiously, warning her that this space was a trap — a giant carnivorous plant that lured people in and swallowed the living whole.
But she did not open her firmly closed lips to ask the man any questions.
"Today's my last day in this godforsaken place, so — hup! From here on out, you're the one who gets to suffer, miss."
The man slung his heavy bag over his shoulder and rose from his seat with a crack of joints.
"Wait a second, mister. What do you mean, a missing persons case? What exactly happened inside this school?"
Instinct and urgency drove her to step into his path as he moved toward the door.
"The cops don't know either. The kids didn't come home for days, and then their belongings just turned up sitting empty in the back seats of a classroom. Whether they ran away or what… the whole group must've lost their minds."
The man scowled as if even recalling it brought bad luck, waving a hand in irritation.
"After that, sometimes the signal cuts out inside the school, and — well. Anyway, next year they're relocating the whole campus into the city. With a location this messed up in the mountains, no wonder the nasty incidents never stop. Hold out until then and these creepy night patrols will be over for good."
"The handover documents, the master key, and the duty log are on that table over there. Read through them and get started. Honestly, if you take the fear out of it, there's not much to do. Take care of yourself."
He fled the Security Office as if escaping.
With a heavy bang, the iron door slammed shut, and a deep silence settled over the old school.
On the table lay the night-specialized equipment the previous guard had left behind. She slotted a high-powered LED flashlight into the holster on her waist belt. The large master key ring that controlled the entire school was secured to her belt with a chain-and-reel holder to prevent loss. On the chest of the vest, she clipped a wireless emergency pager that connected directly to 112 and the security company in a crisis.
For an ordinary security guard, it would have been a perfect, reassuring arsenal.
Ignoring the chill climbing her spine, she picked up the old clipboard from the table.
Beneath the words Night Patrol Zones and Emergency Evacuation Map, a faded floor plan of the school was drawn. The layout was bizarre, shaped by the terrain of a cut-down mountain ridge. The Old Building sat on flat ground, facing a five-story New Building built along the slope, with a hollow athletic field between them. Connecting the two, a three-story Cafeteria Building stacked with the Art Room, the cafeteria, and the gym sat at an awkward angle.
"Even the floor plan is giving me a headache."
Yuna's brow furrowed.
Across the fourth- and fifth-floor plans of the Old Building, someone had scrawled in thick red marker: SEALED — DO NOT GO UP UNDER ANY CIRCUMSTANCES.
The cross-section of the New Building was strange as well. Because of the slope, Basement 2 functionally served as the ground floor — a grotesquely twisted floor system. And on the New Building elevators, an incomprehensible note had been jotted: Left damaged (frozen solid).
"All right. Time for a look around."
Equipment check complete, Yuna switched on the flashlight and stepped out into the corridor beyond the Security Office — and her feet stopped dead.
Creeeak—
An overwhelming structure the floor plan could never have prepared her for crashed into her vision.
Every classroom door along the first-floor corridor — doors that should have been firmly locked — stood open in unison, mouths gaping wide. It wasn't only the first floor, dense with the school's main facilities: the science lab, the administrative office, the principal's office…
When she lifted her head, the center of the building yawned open like a vast well, so that the corridors and classrooms of the second and third floors poured into view all at once — a bizarre panopticon design.
Inside this old structure built to watch every floor without a single blind spot, dozens of black classroom doors were looking down at Yuna alone.
Wooooom. Weeooooom.
Even the monotonous mechanical drone of the rattling fan transformed into a noise that grotesquely amplified the vastness of the space and the isolation within it, stabbing at her eardrums.