Jeong Hae-jun stared at the case files sprawled across his desk. His eyes were bloodshot from an all-night investigation and his shoulders ached, but he couldn't afford even a moment's rest. Pale morning sunlight crept through the window into the office, yet his mind was still mired in the darkness of the night before.
He carefully picked up the topmost folder. On its cover, the title "Lee Seo-ha Disappearance Case" stood out in bold letters. It was the incident of a completely ordinary woman in her twenties, Lee Seo-ha, who had vanished without a trace in the middle of the city a few weeks ago. Hae-jun flipped through the file, reviewing the records from that time once more. Seo-ha had gone missing on her way home after working late overtime. The last person to see her was the security guard of her apartment complex; he testified that right after Seo-ha stepped into the elevator, a crimson mist rose up around the building. When the mist cleared, Seo-ha had vanished, and only her handbag remained, abandoned on the elevator floor. It was as if she had evaporated into thin air. No one wanted to believe the guard's unbelievable story, but the terror he'd experienced was plainly real.
Back then, Hae-jun had initially treated the case as a simple abduction and started his investigation accordingly. However, he soon ran up against circumstances that defied all common sense. Lee Seo-ha's trail had completely broken off after that night, and the nearby CCTVs, obscured by the mist, yielded no useful footage. With not a single decisive piece of evidence, the investigation drifted aimlessly, and the case ultimately fell into limbo, unsolved to this day.
Hae-jun next opened a second folder. The title "Abandoned Warehouse Serial Disappearances" caught his eye. This case had occurred not long after Seo-ha's disappearance. While tracking the whereabouts of a kidnapped child and several other missing persons, Hae-jun's team had ended up in the basement of an abandoned building on the city outskirts, where a shocking confrontation took place. According to the official report, the police special unit engaged in a firefight with an unidentified suspect while rescuing the hostages, and the culprit escaped in the chaos. But what Hae-jun and his colleagues witnessed that day was something no written report could ever fully capture.
Fragments of that nightmarish scene came alive again in his memory… the thick red mist billowing up, a bizarre wail echoing from somewhere, and a pair of eyes glinting from beyond the haze. That night, most of the team had been tormented by hallucinations; Detective Yun Tae-sik had been thrown hard across the room as he shielded a chained-up child, suffering serious injuries. The team had gone in with full equipment and backup, descending into that basement hell. Using flashbangs and a special siren to throw off the shadowy culprit's movements, they had finally spotted a throbbing red "core" in the Specter's chest. Hae-jun took aim and fired a flare gun straight into it. The creature let out an ear-splitting shriek and then shattered into pieces along with the crimson mist.
When the mist dissipated, the basement had been reduced to pandemonium—cracked pillars and debris everywhere. As the team secured the scene and evacuated survivors, they recovered a small pendant with a grotesque pattern on it. Eerily, it resembled the star-marked pendant found only days prior. The surviving victims were in such extreme shock that none could give a coherent statement. Only a sinister laughter echoing in the darkness had hinted at the presence of something—or someone—lurking behind it all. Within the police force, some speculated about accomplices or cult involvement, but Hae-jun's instincts warned that a malevolence beyond the human realm was hiding in the depths of these incidents.
The only tangible clue pulled from that basement was the little pendant necklace. Hae-jun picked up an evidence bag containing the pendant. Through the plastic, the silvery trinket glinted, its surface etched with a razor-sharp emblem. The design was unsettling—vaguely familiar and yet unknown, a shape that sent a chill through him. Hae-jun held the bag up to the light. For an instant, he thought he saw a faint red gleam flicker in the grooves of the pendant's carving.
He closed his eyes for a moment and drew in a slow breath. Lee Seo-ha's disappearance and the warehouse case… Both incidents featured that inexplicable red mist, hallucinations, and the looming shadow of an unknown presence. A prickling wave of goosebumps swept over Hae-jun's skin as he opened his eyes again.
On the desk, files from all three incidents were scattered in a small chaos. Hae-jun gazed past the messy papers toward the incident board mounted on the wall. There, terms like "Red Mist," "Mass Hallucination," and "Black Figure Sightings," as well as the names of the missing people, were scrawled in dense clusters. And at the very center of it all, one name was written in bold strokes: Lee Seo-ha.
In that moment, a whisper that had haunted him like a fading dream the night before drifted through his mind again: "…Seo-ha… she is the key…." He had tried to dismiss it as an auditory hallucination, but a dire premonition was already taking root deep in his gut. Hae-jun grit his teeth, forcing himself to focus. If he couldn't connect all these puzzle pieces and uncover the truth, a fear nagged at him that an even greater catastrophe might be looming on the horizon.
By late morning, near noon, Gwanghwamun Square had mostly returned to a semblance of calm. Even so, signs of the previous night's nightmare still lingered here and there. Dark, dried bloodstains that hadn't yet been cleaned up clung to the pavement, catching the light alongside glittering shards of broken glass. Strips of yellow police line fluttered at the edges of the plaza.
Circling the scene, Detectives Park Jae-min and Choi Do-yoon moved with grim faces, questioning nearby shop owners and security personnel. They spoke with numerous witnesses, but everyone's story was the same: the red mist had appeared in a sudden rush, then vanished just as quickly. Having gleaned little useful information, the two detectives turned toward a nearby office building—the site of last night's security guard fall. The building's entrance still bore scuff marks from the frantic comings and goings of ambulances in the dark hours before dawn.
In the lobby, the building's manager and head of security, Mr. Yoon Young-sik, greeted them with a face drawn tight in fear. He had already given his statement to the police multiple times, yet as he began to speak again his voice quivered.
"K-Kim Cheol-su, the guard, was doing his rooftop patrol… It was early morning, and he'd radioed that he saw something strange on the CCTV, so he went up to check…." Yoon trailed off, swallowing hard. Choi Do-yoon spoke gently, "It's all right, sir. Please take your time. Did Officer Kim say anything over the radio after that?"
"Yes… yes, he did. There was something—" Yoon's eyes darted between the detectives as he struggled to continue. "I heard him say, 'There's someone… no, what is that…' and then he started screaming. He… he was so terrified, we could hear him yelling even through the walkie-talkie…" Yoon wiped a sweaty palm across his brow.
"I checked the CCTV feed again right away," he went on shakily. "But on the monitor it showed Officer Kim alone stepping out onto the roof. I didn't see anyone else there. And yet… he was shouting, acting like he was grappling with an invisible person… swinging at empty air…." The manager's voice faded to a murmur.
"And then I heard his scream, and the fall alarm blared." Yoon squeezed his eyes shut, the memory still raw. "By the time I rushed up to the roof… it was already too late…." He couldn't finish the sentence. His head drooped, grief and guilt etched in his face.
Choi Do-yoon quickly reached out a comforting hand. "Thank you, Mr. Yoon. We know this isn't easy for you. We appreciate your cooperation," he said quietly. Yoon Young-sik managed a weak nod.
Outside, as the two detectives stepped back into the cold midday light, a heavy silence fell between them. They walked a few paces from the building before Park Jae-min finally spoke, his voice low. "So he was alone on the roof… talking to himself, swinging at thin air as if fighting someone…."
"It had to be a hallucination," Choi replied firmly. Park nodded, but his expression remained troubled. "The real problem is: what made him see that hallucination?" he muttered.
He cast his gaze around the square. Despite the sun high overhead, an unsettling pall still clung to the place, as if the air itself remembered the terror of the night. A few passersby kept glancing at the taped-off areas, whispering among themselves—clearly the horror of what had happened had not yet faded from memory.
Choi exhaled and rubbed the back of his neck. "People are talking about poison gas or some kind of drug attack… but forensics hasn't found a shred of evidence for any substance. That just makes everyone more scared."
Park let out a small sigh. "Honestly, if the labs had discovered some chemical agent, it might actually ease folks' minds. At least we'd have something concrete to blame. But now…." He lowered his voice, hesitating. "Now there are even rumors going around that… that it was a ghost or a possession." The words tasted absurd, even to him, and yet he couldn't dismiss them outright.
Neither detective wanted to say it out loud, but both had felt it — the unsettling sense that something beyond the ordinary was at work. With nothing left to add, they fell quiet. For a moment, their eyes drifted upward to the rooftop where Officer Kim had fallen. In the bright light of day, the roof's shadow still seemed unnaturally dark.
Park Jae-min felt a nameless anxiety unfurling in his chest, spreading slowly like a stain.
Meanwhile, Detective Yun Tae-sik sat at his desk back at Gangbuk Precinct, staring anxiously at his phone. Since early morning he had been waiting for a call—any word on the detailed analysis of the reddish particles they'd collected at Gwanghwamun Square. His shoulder was still wrapped in fresh bandages from the night's injuries, but he paid it no mind. He simply couldn't relax. His foot tapped restlessly against the floor as he tried and failed to steady his breathing.
At last, the phone buzzed in his hand. Yun snatched it up before the first vibration even ended. The caller ID showed Dr. Han So-young, the forensic expert from the National Forensics Service. He pressed the phone to his ear. "Yes, Dr. Han—this is Detective Yun."
A tense voice crackled through the line. "Detective Yun, it's me, Han So-young. We just received the results from the lab…" She paused, as if bracing herself. "I have to say, the findings are… difficult to believe. I'm not even sure how to explain them."
Yun Tae-sik's heart sank. He swallowed and asked, "What did you find?"
"Well," Dr. Han began carefully, "first of all, it's not any kind of conventional chemical agent. We didn't detect any toxic gas or narcotics or anything like that." She drew a breath. "Instead… we found signs of biological matter."
Yun's eyebrows knit in confusion. "Biological matter?"
"Yes. In fact… some components of blood were identified in those red particles, along with fragments of organic tissue." Her words came out in an uneasy rush.
"Blood components?" Yun repeated, bolting upright in his chair.
"Exactly. Hemoglobin, to be specific — an iron-rich protein in blood — showed up at extraordinarily high levels. And there were bits of proteins and organic compounds as well. The best way I can describe it is… it's as if tiny droplets of blood dried and pulverized into dust."
For a moment, Yun Tae-sik forgot to breathe. He couldn't find any words. On the other end of the line, Dr. Han continued, her tone grim. "And… there's something even stranger. A few hours after we collected the samples, the particles started to change. Their red color faded and the material began disintegrating rapidly. It's like once those particles were taken out of their original environment, they broke down almost immediately. There's no scientific precedent for this kind of behavior."
Yun pressed the phone tighter to his ear, a cold sweat breaking out on his palm. He struggled to process what he was hearing. "So… in the end, we still can't say what these particles are," he said quietly, finishing her thought. His voice was flat with dread.
Dr. Han let out a frustrated sigh. "I'm sorry. We'll keep testing what samples we have left, but as of now, we have no idea how to categorize this. It's unlike any dust or residue we've ever seen."
"I understand. Thank you, Doctor," Yun replied softly. "Please contact me right away if anything new turns up." He ended the call and lowered the phone from his ear. For a long moment, he simply sat there, the silence of the office pressing in on him.
He realized his hand was trembling; a sheen of cold perspiration coated his fingers. The facts Dr. Han had relayed swirled violently in his mind. Red particles that are essentially powdered human blood? Yun's stomach churned at the thought. If that was true, then what kind of nightmare were they really dealing with? Who—or what—could possibly be behind an atrocity like this? It defied imagination.
Yun took a long, unsteady breath and rose from his seat. He had to tell Detective Jeong Hae-jun immediately. Fighting the dizziness in his head, he headed straight for the precinct conference room where Hae-jun was working. His instincts screamed that this confirmed what they'd all feared: behind the red mist and the hallucinations lurked something beyond any human foe or scientific explanation—something truly otherworldly.
Yun pushed open the conference room door. Inside, Jeong Hae-jun sat alone at the long table amid piles of documents and photos. At Yun's entrance, Hae-jun lifted his head expectantly. One look at Yun's face, and a knowing sharpness flashed in Hae-jun's eyes, as if he had already anticipated bad news.
Yun's throat felt dry. In a hoarse voice, he delivered the report. "Detective… the analysis from NFS came in. The red particles from the scene… they turned out to be some kind of unidentified organic matter. The lab detected key components of blood in them, and… they said it's not something that can exist under normal conditions…." He trailed off, unsure how to even finish that sentence.
Hae-jun had already turned toward the window, where the sky was stained with hues of deep red and orange. Evening was approaching, the sun bleeding out over the city. "At first it took one person," he murmured, almost to himself. "And now it has thrown countless people into terror. Clearly, whatever 'it' is, it's acting with intent…." His voice was bitter, laced with quiet fury.
He stood and faced the wall where Lee Seo-ha's name was written among the many clues. The dying sunlight cast long shadows across the room. "We can't keep looking at this through the lens of ordinary logic anymore," Hae-jun said, voice low but resolved. His hands clenched into fists at his sides. "If we're going to find the source of all this, we need to start thinking outside the bounds of everything we know. Call it a ghost, a demon, whatever it is—we're going to track it down and put a stop to it."
Yun Tae-sik nodded gravely, jaw tight. A chill ran through him at Hae-jun's words, but he knew the detective was right. They had crossed into territory where their only choice was to confront the impossible.
Neither man spoke again. Together, they turned to look out the window at the sun sinking below the skyline. The crimson glow of twilight slowly yielded to darkness as the veil of night descended over Seoul. In that gathering darkness, an unsettling thought weighed on both their minds: somewhere out there, hidden in the shadows, an unknown presence might still be watching them.