It was just past 2 a.m. at Gwanghwamun Square in Seoul. Normally at that hour the area would be mostly empty and quiet, but tonight a faint red fog had settled thickly over the plaza, casting an eerie, unsettling atmosphere. The streetlights flickered anxiously within the crimson haze, and beyond the fog the silhouettes of the grand statues of King Sejong and Admiral Yi Sun-sin loomed faintly. The once-familiar cityscape, stained red by the fog, was transforming into something alien and unrecognizable.
On the roof of a nearby twenty-story office building, night security guard Choi Young-sik stood at the edge, scanning his surroundings. In the silence, he murmured to himself, "I could have sworn someone came up here...." A strange prickling at his ears set him on edge, and he raised his flashlight high. Beyond the rooftop's ledge, the darkness seemed to ripple, and in the ominous silence he thought he heard the faint sound of a giggle.
Heart pounding, Choi Young-sik tensed and shouted into the emptiness, "Who's there?" He was met with no response—nothing but the thick silence. Not even the scuffle of a footstep came back to him. Instead, from somewhere behind him, a child's soft laughter drifted through the air. Choi Young-sik jumped, a chill racing down his spine. He tried to reassure himself—there was no way a child could be on the rooftop at two in the morning—yet his heart was thudding madly in his chest.
He swung his flashlight toward the source of the laugh, and its beam cut through the fog. There, a small shape flickered at the very edge of the light. It was an indistinct silhouette, but it unmistakably looked like a child. The figure was crouched in a corner of the roof, clutching a broken doll in its arms.
"Wha—? There's... actually a kid here?" Choi Young-sik gasped. At that moment, the small figure slowly raised its head and looked straight at him. Where its face should have been, there was nothing—only gaping black holes in place of eyes, nose, and mouth. The instant those empty voids seemed to stare into him, Choi Young-sik's breath caught. He stumbled back a step, suddenly unable to make a sound.
A low muttering drifted from the figure in the voice of a little girl. "N-no... it's not me... I shouldn't be here..." At the same time, the part of its face that might have been a mouth began to rip open, stretching into a grotesque grin.
Choi Young-sik let out a choked cry. In that moment his legs turned to jelly. He staggered and fell back, crashing hard against the rooftop railing. His mind reeled; the sight he had just witnessed couldn't possibly be real.
As he teetered against the railing, he saw the hazy red fog swirling around the child's form, slowly enveloping it. The fog billowed and writhed as though alive—he had the horrific impression it was stretching out toward him like tentacles. Overcome with terror, Choi Young-sik whirled around in a desperate panic.
"No... no, stay back!" he shrieked. Stumbling backward in blind fear, his heel caught on the lip of the roof's ledge. In an instant, he lost his balance. His body tipped backward over the edge and, before he could even scream, he was plummeting through the open air.
Down on the ground, at the edge of Gwanghwamun Square, a man's body struck the sidewalk with a sickening thud.
"Somebody fell!" a passing taxi driver shouted, screeching his cab to a halt, and in that instant, the red fog–shrouded darkness erupted into pandemonium.
At the same time, an early-morning street cleaner working near the plaza was witnessing an eerie sight of his own. He had stopped gathering trash and was staring blankly up at the sky—because beyond the veil of red mist, enormous shapes that shouldn't exist were stirring. It wasn't the familiar statues of the square; something far larger—a colossal, dark-red shadow—was covering the sky. It looked as if a demon's gigantic form was peering down through the fog.
The cleaner's hands trembled violently and he stumbled back a step. Before his eyes, the stone guardian statue in front of Gwanghwamun Gate appeared to writhe and warp, transforming into a demon's shape with a grotesque grin.
"A-a demon...!" he stammered. The middle-aged cleaner collapsed to the ground, clutching his head. As reality and illusion swirled together in his vision, he began wailing in terror.
As the red fog slowly swallowed up the Gwanghwamun area, everyone trapped inside it fell into their own personal nightmares. One pedestrian saw a horrifying vision of blood pouring down around him like rain and let out a bone-chilling scream. Another young woman stood in the middle of the street, pounding on her stomach with both fists as she alternated between wild laughter and hysterical sobbing. "Get out... I said get out! Get out of me!" she shrieked, her voice breaking with manic fury—as if something inside her needed to be expelled—before collapsing into gut-wrenching sobs.
Dozens of people throughout the plaza were all at once losing their grip on reality and becoming trapped in private hells of their own, the scene devolving into pure chaos.
Officer Kim Hyung-gu, who had been on patrol nearby, witnessed the security guard's fall and rushed over to control the scene. However, after he too inhaled the red mist, a nightmare tableau unfolded before his eyes as well. Before he even realized it, Officer Kim had drawn his service pistol and was waving it frantically at thin air around him. Cold sweat beaded on his forehead. "Get back! Stay away from me!" he screamed, aiming his gun at an unseen assailant. His face was flushed, and as he glared into empty space, his eyes were wild with terror and madness.
Around that time, in the corridor of Seoul National University Hospital's emergency ward, Detective Jeong Hae-jun was pacing anxiously, clutching his phone. Just a few hours ago, during a raid on an abandoned building the night before, Detective Yoon Tae-sik—one of his teammates—had been gravely injured while trying to rescue a young child. Thankfully, emergency surgery had been successful, but Yoon Tae-sik had yet to regain consciousness. Jeong Hae-jun had stayed in the hallway, unwilling to leave his critically wounded colleague's side.
He sat hunched on a chair outside the operating room, silently repeating the same plea over and over in his mind. Please, hang in there... The nightmare memory of the red fog and the Specter still lingered in his head, but at that moment the fate of his treasured colleague was far more urgent.
Just then, the phone in his hand rang shrilly, shattering the quiet. Jeong Hae-jun snapped to attention and answered immediately.
"Detective Jeong, it's an emergency!" a fellow officer shouted over the line. "At Gwanghwamun Square... citizens are suddenly showing strange symptoms all at once…."
As the panicked voice of his squad member poured from the receiver, Jeong Hae-jun's eyes sharpened. He leapt up from his seat and looked toward the ER. Through the small window, he saw that the light above the operating room doors had just switched off and a few medical staff were beginning to emerge. He ached to check on Yoon Tae-sik's condition right away—but now even more lives were in immediate danger elsewhere.
At that very moment, a weak voice called out beside him, "...Detective."
He turned to find Detective Park Jae-min standing there, face deathly pale. It was Park—just a few days ago, at the site of the red fog incident, he had witnessed bizarre horrors and passed out. He'd been hospitalized since, and was only now in the middle of signing his discharge papers. He wasn't fully recovered yet, but Park Jae-min's eyes burned with determination.
Jeong Hae-jun's own eyes widened. "Jae-min, you're in no shape for this," he protested.
But Park Jae-min answered in a raw, trembling voice, "I—I'll go. We have to stop this before it's too late. Detective, I'm going in Detective Yoon's place."
Park Jae-min had experienced the red fog firsthand; he knew better than anyone how terrifying this situation was. Even so, his sense of duty—to help his team and protect the public—was stronger than his fear.
Jeong Hae-jun regarded his younger colleague for a brief moment, jaw tight. A teammate who had only just collapsed days ago was now volunteering to run toward the danger on unsteady legs—it wasn't something he could allow lightly. But the screams and frantic radio calls still crackling over the phone made the decision for him. People were in peril in the heart of Gwanghwamun. There was no time to hesitate.
He clenched his teeth and gave a curt nod. "...All right. But don't overdo it. Just assess the situation and call for backup immediately, got it?"
Moments later, the wail of sirens rose through the Seoul night, cutting a path through the darkness. Jeong Hae-jun and Park Jae-min sped toward the scene in a police cruiser. At the wheel was Detective Choi Do-yoon, who had come racing at the emergency call. Choi had been temporarily assigned to the team during the last incident and afterward volunteered to stay on. He'd been manning the situation room at headquarters when Jeong's call came, and he bolted out immediately to join them.
Choi Do-yoon kept his voice steady as he rattled off the latest report. "So far, at least twenty injuries have been reported. Ambulances and fire crews are en route to the plaza. The units that arrived ahead of us have set up a perimeter."
Choi had endured the uncanny horrors of the red fog once before, yet as they neared the site again he still felt a wave of tension course through him. Even so, his eyes remained calm and sharp.
Staring out the window at the strobing blue and red lights, Jeong Hae-jun spoke in a low voice. "Once we get there, focus on securing civilian safety first. Detective Choi, when backup arrives, coordinate with them and handle communications."
"Understood," Choi answered at once.
In the back seat, Park Jae-min bit down hard on his lip, as if trying to stave off a rising tide of anxiety. Clenching his fists, he murmured, "So... it's the red fog again, right?"
Jeong Hae-jun did not reply. He rested a hand on the pistol holstered at his hip. It was loaded with ordinary bullets that would likely prove useless against what lay ahead—but it was better than nothing. Closing his eyes for a brief second, Jeong grit his teeth. The very thing he'd feared was now happening. A flash of memory seared through his mind: the abandoned building where he had first encountered that nightmare of red fog. This time it's Gwanghwamun... the middle of downtown.
He opened his eyes and said quietly, "Step on it."
Meanwhile, in a hospital bed back at the ER, Detective Yoon Tae-sik hovered in a fog of half-consciousness, straining to listen. There was commotion all around him. Still heavy with fading anesthesia, he could hear the faint wail of distant sirens through the haze.
Yoon Tae-sik forced his eyes open, but everything was out of focus. The faint smell of antiseptic hung in his nose, and above him the white hospital ceiling swam into view. He tried to push himself upright, and bolts of pain shot through his bandaged shoulder and side. He bit back a groan, struggling to piece together his memories.
The last thing he remembered was that basement shrouded in red fog—the moment he had thrown himself in front of the Kidnapper Demon's attack while shielding a child. Everything after that was darkness.
I'm alive... Yoon Tae-sik realized, hardly able to believe it. He exhaled a shaky breath, a hint of relief crossing his face. But almost immediately, a new thought flashed through his mind like lightning. The fog... the red fog is back...
The distant sirens did not sound like a good sign. Fighting through the pain, Yoon Tae-sik managed to sit up and look around. An IV drip was taped into his arm, and his shoulder was wrapped tightly in layers of bandages, throbbing with every heartbeat. He knew he couldn't just lie there. His eyes fell on his shirt, neatly folded on the chair beside the bed. Gritting his teeth, Yoon Tae-sik ripped out the IV without hesitation. An alarm started beeping, but he ignored it, grabbing his clothes with trembling hands. "Agh...!" He couldn't help but gasp as fabric brushed against his raw wound. Every slight movement sent fresh pain lancing through his body, but he grit his teeth and endured it. He thought of Detective Jeong and the others. It wasn't over yet.
Steadying his breathing, Yoon Tae-sik fumbled open the small locker beside the bed. He had to get out of here before the doctors and nurses noticed. Shrugging on his bloodstained shirt, he staggered to the door and slipped out into the corridor. A wave of dizziness washed over him and his vision dimmed; he nearly went down before he caught himself against the wall.
He gave a breathless, bitter laugh. "Ha... Am I really thinking of going back out there in this condition? I must be insane..." he muttered under his breath. Still, he didn't stop. Yoon Tae-sik pushed open the stairwell door at the end of the hallway, bracing himself as a blast of chilly pre-dawn air hit him. The nightmare of the red fog was rearing its head once again—but one thought filled Yoon Tae-sik's mind, crowding out all else: I have to go. I need to be there with them.
His body was battered and broken, but he forced himself down the stairs, step by shaky step, heading toward his team and the chaos awaiting them.
Back at Gwanghwamun Square, a police cruiser screeched to a halt, tires skidding against the pavement. The moment Jeong Hae-jun, Park Jae-min, and Choi Do-yoon stepped out of the car, a chill gripped them. Something in the atmosphere was deeply wrong. An eerie energy clung to the air, and the red fog blanketing the plaza was even denser than they had feared. The haze was so thick that they could barely see a few meters ahead. From somewhere within that crimson murk came the sound of mingled screams and sobs, as if the plaza had become a vision of hell.
Jeong Hae-jun swiftly took in the scene. "Park, check the injured first!" he shouted. Park Jae-min nodded and sprinted toward a cluster of bodies sprawled on the ground. All around, in the blood-red fog, people lay strewn across the plaza—some unconscious, some quaking in fear and babbling at things that weren't there.
Park spotted a city cleaner—the very same middle-aged man—sitting dazed on the ground, hugging himself and rocking. Park knelt and gripped the man's shoulder firmly. "It's all right. You're safe now," he said gently. Perhaps it was Park's solid build or his calm, reassuring tone, but the cleaner's wild, unfocused eyes seemed to regain a hint of clarity as he looked up at the young detective.
Just then, the man's gaze drifted over Park's shoulder to something behind him—and his eyes widened in renewed fear. He lifted a shaking hand to point, lips quivering. "B-behind you...!"
Park Jae-min whipped his head around in the direction the cleaner indicated. Through the swirling fog, a pitch-black figure slid silently past. Its outline was just barely visible—a shape that might have been human, but could have been an animal. Park's heart jolted into his throat. Is it... here again?
In his mind, he could still see that terrible crimson form that had overwhelmed him days ago. The memory made him flinch on instinct. But then, in his head, he heard Detective Jeong's voice as clearly as if he were standing there: Stay focused. Park Jae-min took a steadying breath and steeled himself. He hefted the trembling cleaner up from the ground and draped the man's arm over his shoulder. "We need to move. Come on—stand up," he urged. The cleaner wobbled on his feet, barely able to stand, but Park supported his weight and started guiding him away, eyes scanning for a safe spot to take shelter.
Meanwhile, Jeong Hae-jun followed the increasing uproar toward the center of the square. Beyond the wall of red fog, people's screams kept bursting out, one after another. "A demon… a demon is here!" someone was shouting. Jeong saw a man sitting on the ground, shrieking at thin air. Jeong sprinted over and grabbed the man to keep him from scrambling away.
"It's okay! I'm a police officer," Jeong said, trying to steady the panicked man. "I'm going to get you out of here—"
Before he could finish, the man's eyes bulged in wild terror. He threw off Jeong's arm and let out a crazed scream. "Get away! Don't come near me! You… you're one of them too, aren't you?!"
Delirious with fear, the man lunged to his feet and tried to flee from the specters only he could see—apparently seeing even Jeong as another monster from his nightmares. Jeong cursed under his breath and moved decisively, wrestling the thrashing man into a restrained hold and dragging him off to the side.
At that moment, a sharp crack of gunfire rang out from somewhere behind them.