Gwanghwamun Station – Entrance to the underground connecting passage.
Jung Hae-jun cinched the bandage on his left arm one more time, pulling it tight. A stab of pain shot through the torn flesh beneath, but he paid it no mind. Not long ago, he'd been locked in a desperate struggle with the specter in the storm sewer, a hallucination-weaving fiend that he and his team had finally chased and cornered here. The creature was wounded and hiding somewhere in the darkness ahead, nursing its injuries.
Hae-jun drew in a deep breath. The clammy subterranean air reeked of iron from the crimson mist and the acrid tang of gunpowder, stinging his nose. Overhead, emergency lights flickered irregularly. The walls were scarred with blackened electrical wiring and littered with chunks of broken concrete. All around them lay the raw aftermath of their battle moments before.
"Everyone okay?" he asked quietly. Yoon Tae-sik, Choi Do-yoon, and Park Jae-min all responded with silent nods. Their breathing was ragged, but determination still shone in their eyes.
While they took a moment to reload and regroup, Hae-jun quickly reviewed the plan. "It definitely fled into the subway station," he said under his breath. "Probably holed up down on the lower level, somewhere dark and confined like a B3 mechanical room." He swept his flashlight over a trail of sticky red slime on the floor. A foul odor, like charred flesh, wafted up from the viscous streak. It was undoubtedly the specter's blood, spilled as it was injured. Hae-jun grit his teeth and set his jaw. The fact that the thing was leaving such a tangible trail meant one thing: this time, they could finish it.
The interior of Gwanghwamun Station was already devoid of civilians at this late hour, and police had completely cordoned off the area, keeping all bystanders out. Hae-jun spoke briefly into his radio to verify the backup team's position. Everything was ready. He cast a resolute glance at his fellow officers. "Move out," he ordered in a low, firm voice.
Guns safeties off, the four of them advanced cautiously down the passage into the station's depths. A place that would ordinarily be packed with late-night crowds was now eerily empty, as if the bustling station had been a lie all along. After the last train's departure, the platform and concourse had gone dark and silent, a deep stillness settling over everything. In the faint glow of the emergency lights, thin tendrils of lingering red mist snaked along the floor, swirling in uncanny patterns. The stopped escalators and blank, dead arrival boards only heightened the sense of desolation.
To Hae-jun, this scene felt less like reality and more like a living nightmare. The only sound was the low hum of the ventilation fans droning in his ears. He swept his tense gaze over the surroundings. Anticipating potential illusions, Hae-jun pulled a small LED light from his belt. He clicked it on and flashed it in a specific pre-arranged pattern. The light blinked at 0.8-second intervals – the signal the team had established to confirm they were still in reality. In response, Yoon Tae-sik and Choi Do-yoon each flickered their own flashlights in the same rhythm to answer. The four men, reassured of each other's presence and clarity of mind, descended the stairwell to the lower level.
They moved slowly, maintaining a half-moon formation with Hae-jun at the center. Hae-jun assigned Park Jae-min to guard the rear. Park stayed back at the tunnel entrance, gripping his pistol tightly as he watched their backs. Choi Do-yoon and Yoon Tae-sik flanked Hae-jun on left and right, matching his pace to keep the formation intact. The further they ventured into the darkness below, the colder and damper the air became. A mix of mold and rust filled their lungs, making it hard to breathe. Somewhere in the distance, water dripped steadily – plip, plip – the sound echoing down the corridor.
Hae-jun felt a chill brush the back of his neck and abruptly halted. In that instant, beyond a darkened shop window to his side, he glimpsed a shadow flit by. His heart plummeted. Instinctively, he swung his gun toward the glass and shone his light. The beam revealed nothing but the reflection of his own trembling light and silhouette in the mirror-like pane. No other movement. Nothing there at all.
Steadying his pounding heart, Hae-jun forced himself to move forward again, though every nerve in his body remained on edge. Before long, a heavy metal door loomed at the bottom of the stairs. Hae-jun immediately raised a clenched fist, signaling the others to stop. Drawing closer, he could make out a sign on the door: "Machine Room B3." A bloody handprint, roughly the size of a human palm, was smeared across the steel surface. From the gap beneath the door, a thin ribbon of red mist seeped out, curling into the air.
Hae-jun's eyes flashed. This is it.
"This is the place," he whispered, motioning for Park to remain on guard at their rear. With hand signals, he directed Yoon and Choi to take positions on either side of the doorframe, flanking the entrance.
The metal door was ajar, left slightly open and quivering ever so gently. Pressing himself flat against the wall, Hae-jun aimed the muzzle of his pistol through the narrow opening. In his magazine were rounds specially coated with holy water – the team had doused their bullets in it beforehand, a desperate countermeasure against the supernatural. Whether it would actually have any effect was unknown, but they were prepared to try anything in this final stand.
Choi Do-yoon carefully slid a compact thermal camera through the crack in the door. He studied the display for a few seconds, then gave a nod, whispering in the faintest voice, "It's in there… high on the right, hiding behind the piping."
Hae-jun leaned in to peer at the screen beside Choi. The machine room beyond was cluttered with tangled pipes and machinery. On a high section of wall in the back, a heat signature stood out against the cooler surroundings: a crouching red shape. Blurry but unmistakably humanoid in outline—the specter. Like a spider clinging to the wall, it was completely motionless, one of its arms hanging at an odd, limp angle. The injury from their earlier fight had clearly taken its toll.
Hae-jun held his breath, the pain in his left arm forgotten. The final confrontation was right in front of them.
Fixing three fingers in the air, Hae-jun silently counted down—three, two, one—then drew a breath and slammed the door open with all his might. He immediately dropped low and burst into the machine room. At the same instant, Yoon Tae-sik hurled the flashbang they had prepared without a second's hesitation.
BOOM!
With an explosive crack, a blinding flash filled the room. In a split second, the darkness was painted white, the machine room laid bare as if under the midday sun. And in that blaze of light, the specter's grotesque form was exposed, crouched in the corner where wall met ceiling.
It was enormous—well over two meters tall—with a body of roiling smoke and mist. Countless faces bubbled up within its vaporous torso only to dissolve and emerge again, a nightmare collage. Red eyes darted here and there among the writhing faces, gleaming with malignant intelligence. The specter, suddenly forced into the harsh light, let out a scream from deep in its throat.
"Shrieeek—!"
A metallic screech, like nails on metal, tore through the cramped machine room, rattling the very air.
"Fire!" Hae-jun shouted.
On his command, he squeezed the trigger, and almost simultaneously Choi Do-yoon trained his own gun on the specter and opened fire.
Bang! Bang!
The deafening reports of two gunshots rang out back to back, pummeling their eardrums. The holy-water-coated bullets cut white-hot paths through the flash's dying afterglow as they streaked toward the target. One round punched clean through the specter's shoulder, spraying red misty flesh as a burst of white vapor sizzled into the air. The other round went wide, smashing into concrete and blasting out a spray of shards.
The specter recoiled in agony, its massive form twisting as if wracked by pain. One of its giant arms lost cohesion, disintegrating into a cloud of red vapor before evaporating entirely. It was a solid hit.
But the fight was far from over. The specter's remaining eyes flared with hate, blazing back to life with renewed ferocity. In the next instant, the lingering afterimage of the flashbang faded, and darkness crashed down over the room once more.
Hae-jun swung his flashlight around urgently, the beam jittering through the gloom—but the specter's shape was nowhere to be seen.
All at once, a low susurrus of whispers slithered from every direction, coiling around the four officers:
"...I know your deepest secret..."
The voice was faint, yet it whispered directly into their ears as if someone crouched right behind them, breath hot on their necks. Its gloomy, icy resonance bored into Hae-jun's skull, and his vision swam.
It's a hallucination attack...! he realized—but too late. His mind registered the danger an instant after it had already sunk its claws in. Reality around him rippled like a stone tossed in water. The pitch-black machine room walls wavered and bled into strange new shapes.
With the last of its strength, the specter was assaulting all four of their minds at once.
"Hhk—!" Hae-jun choked, gasping for air as he fought to stay upright. He struggled to resist, but then—suddenly—two blood-soaked hands flashed before his eyes, lunging out of the darkness to grab his arm. A vision—an illusion—raced past him. At the same time, someone's agonized scream echoed inside his head:
"It's your fault... All of it is your fault!"
A familiar voice, ringing from far away like a ghostly accusation.
Hae-jun jerked his head violently, purely on instinct. It's just an illusion! It's not real! he shouted in his mind, trying to force the thought through the terror. But it was no use—ragged sobs and sinister whispers still flooded his ears, relentless. Cold sweat streamed down his body. A stabbing pain bored into his temples, as if needles were being driven into his skull.
Through hazy vision, he glanced to the side. Choi Do-yoon had fallen to his knees, clutching his head in his hands, about to collapse. Yoon Tae-sik stood trembling with eyes wide, face ashen, his pistol wavering unsteadily at phantoms in the void. Each of them was seeing their own worst nightmare playing out before them.
"St… stop… please… don't…" Yoon Tae-sik whimpered faintly, his whole body shaking. Hae-jun saw Yoon's finger convulse on the trigger, inches away from a panicked misfire at one of their own. A single accidental shot in this state could be fatal.
"Yoon Tae-sik, snap out of it!" Hae-jun managed to cry out hoarsely, but Tae-sik's gaze was still unfocused and wild. The numbers they'd drilled as a call-and-response code—meant to pierce through illusions—had been utterly overridden by the specter's psychic assault.
If this continues, we're finished—Hae-jun realized with a surge of alarm. What they needed right now wasn't the regimented signal or code; it was something to remind everyone that they still shared the same reality, something to trust in together.
Gritting his teeth, Hae-jun drew a breath deep into his lungs and bellowed with all his might, "We trust each other!"
His shout ripped through the darkness like a thunderclap. For a split second, Choi Do-yoon's pupils flickered, then refocused with clarity. Yoon Tae-sik's trembling finger halted and went still.
It was their reality check—delivered from the heart. Hae-jun's cry had jolted his team back to their senses.
While the specter's disembodied whisper faltered for that brief moment, Yoon Tae-sik seized the chance and jabbed at his phone screen.
Bzzzzt…
A harsh crackle sounded from a small speaker, followed by an eerie wail played in reverse. It was the very scream the specter had emitted moments ago, now warped and inverted. A low, mournful keen reverberated through the space, like the wailing of a vengeful spirit turned on itself.
"Grraghh… urk…" A ghastly reverberation spread through the darkness, and the invisible specter visibly recoiled, its form flickering into view for an instant. In a far corner of the machine room, a silhouette of red mist quivered unevenly. Thanks to Tae-sik's quick thinking, the specter had been thrown into confusion by the sound of its own wail played backwards, halting its attack.
This was their chance.
Hae-jun's eyes flashed as he caught sight of the specter's location. The creature was slithering up along the wall toward the ceiling, as if trying to flee.
"Above, toward the ceiling!" Hae-jun shouted, striding forward toward the specter's shifting outline. Pain flared hotly from the wound in his left arm with each step, but he ignored it. In Hae-jun's vision, the prey was clearly attempting to escape, and he had no intention of letting that happen.
"You're not taking one more step," he growled, voice low and steely.
With that, Hae-jun squeezed the trigger on his remaining rounds in quick succession.
Bang! Bang! Bang!
A volley of gunshots rang out in rapid sequence, and bullets slammed into the specter's massive form. At nearly the same moment, Choi Do-yoon's muzzle flashed as he fired as well. The holy water-laced rounds tore through the specter's central mass.
"Guaaaargh—!" The specter's shriek rose an octave into a piercing scream. Its myriad red eyes flickered erratically, whipping in all directions. And finally, the crimson mist body began to waver as if caught in a violent vortex. The specter's form swirled, then started to dissolve, like a shadow melting away under the morning sun.
Its scream warped from a high, sharp cry into a wet, choking animalistic squeal. At last, with a final pig-like shriek, the sound cut off abruptly. In that instant, all the red mist shards that had been swirling in the air shuddered, then fell limp, raining down like ash to the floor.
The long, grueling battle was over at last.
In the crushing silence that followed, Hae-jun slowly released his finger from the trigger. Where the towering shape of red mist had loomed, only tiny crimson embers now drifted in the air like motes of dust. It felt as if he were waking from a nightmare—the sense of reality gradually returning to him.
Just then, a distant crackle broke the quiet from the direction of the platform, followed by the warbling voice of the station PA system: "The current time is 5:12 AM. The first train will be arriving shortly. Passengers, please stand behind the safety line."
It was the sound of the first train of the morning — an announcement of dawn's approach. As if to signal that the hellish night was ending and the world of ordinary life was coming back.
"D-Damn... is it over?" Yoon Tae-sik muttered under his breath, sounding incredulous.
Hae-jun slowly surveyed the scene. Choi Do-yoon had practically collapsed to the floor, sitting down hard as he gulped in air. The thermal camera he'd dropped lay on the ground next to him, its display showing no heat signatures at all. Yoon Tae-sik wiped sweat from his brow, his hands trembling as he lowered his gun. Park Jae-min, who had been tensely watching the doorway, now approached. The four teammates exchanged glances, their eyes reflecting equal parts relief at their victory and a dazed disbelief that they were still alive.
Hae-jun gingerly cradled his left arm, which was throbbing with a fiery pain. Through the tattered sleeve of his jacket, he could see his skin swollen and red around the wound. He grimaced and lifted his head, clamping down on the pain. "Looks like... we're all still alive," he said quietly. There was a hint of a wry smile in his voice as he spoke.
Yoon Tae-sik and Choi Do-yoon managed weak grins as they braced against each other and rose unsteadily to their feet. Park Jae-min exhaled a deep sigh of relief.
As Hae-jun's gaze swept the area, something sparkled on the floor at the center of the machine room. It was near the spot where the specter's core had been moments ago.
"There… something's there," he said. He walked forward slowly and crouched down. On the ground lay a small shard of red crystal, about the size of the tip of a finger. It glimmered faintly, like a fragment of ruby.
Hae-jun picked it up with gloved fingers. The shard's surface was smooth, and right in its center was an indistinct yet unmistakable carving of a star.
"What is… that?" Choi Do-yoon asked, curiosity lighting his weary face as he stepped closer.
Hae-jun held the crimson fragment up to his flashlight. In the beam, the star-shaped mark etched in the middle was faint but clear.
Hae-jun's heart began to thump faster. In that moment, he remembered the delirious mumble Officer Kim Hyung-gu had uttered when they'd rescued him earlier: "...There's someone… in the mist…." And he recalled, too, the sly whisper that the specter's illusion had hissed at them: "I know your deepest secret…." Those words swirled in his mind.
Hae-jun's fist closed tightly around the red crystal shard. This star-shaped symbol was undoubtedly a clue—evidence hinting at the existence of some "someone" lurking behind all these incidents up to now.
"Good work, everyone," Hae-jun said softly into the silence. He then added in a firm voice, "Officially, we're reporting this case as a gas leak accident."
Park Jae-min gave a bitter little smile and nodded. They all knew that orders from above and public panic over the truth meant that the existence of any supernatural entity and the red mist would be covered up.
Yet all four of them were acutely aware that what they had just gone through was no hallucination or gas-induced illusion. A heavy silence fell as their eyes met, each person reading the unspoken understanding in the others' gaze.
The long night of battle begun by the red mist had finally ended.
But Hae-jun's instincts were sounding an alarm. The small red crystal shard in his hand… the star-shaped emblem carved into it… this felt like a grim key heralding a new beginning to the whole mystery.
Hae-jun could not take his eyes off the diminutive shard glowing ominously in his palm. The faint star pattern stood out clearly in his vision. Even in the cold dawn air, the fragment still glowed softly, like an ember that had yet to cool.
Pressing his lips into a firm line, Hae-jun stared hard at it. He could feel his heart starting to pound faster again, yet he refused to look away. Whatever that crimson star truly signified, he knew one thing: he would have to be ready to face it.
Before Hae-jun's eyes, the star-shaped mark engraved on the red crystal shard gradually grew sharper in relief. And that foreboding starlight flickered back to life within his own gaze.