At exactly nine in the morning, the Violent Crimes Unit headquarters in Seoul turned into a war room. The cold white lights reflected off the face of Detective Kim, who was analyzing the crime scene with an eye that missed nothing.
"This wasn't just a killing—it was a theatrical performance conducted remotely," Kim said, pointing at a timeline displayed on the screen. "The criminal didn't touch the final crime scene with his own hands… he used the hands of others."
Detective Kim began explaining the scheme to the team: "We have two intermediaries, neither aware of the other. The first intermediary, whom we've already interrogated, had a purely logistical role: deliver the bag to the last restroom at exactly 18:15 and leave it there. He was merely a 'carrier' who was blackmailed over his extramarital affairs."
Kim then tapped the control panel, revealing images of three individuals: "According to the surveillance cameras, during the time gap between the bag being placed and the head being discovered at 18:25, only three people entered that restroom. One of them is our key… the second intermediary."
Inside Interrogation Room (4), a man sat hunched over as if the weight of the world rested on his shoulders. He wasn't a professional criminal, but a man in a formal suit suggesting a high-ranking position—yet his eyes overflowed with fear.
He began speaking in a trembling voice: "I swear I didn't know what was inside that sphere… it was solid, heavy, and wrapped in something like opaque plastic."
Kim leaned on the table, narrowing his eyes: "Why did you do it?"
The man broke down crying: "The messages… they wouldn't stop! They came from different international numbers every time. Photos of me from high school… I was a reckless teenager, I used to bully my classmates cruelly… If those photos were exposed now, I'd lose my prestigious job immediately. I have a wife and two children… I can't let my family fall apart because of a mistake I made twenty years ago!"
Struggling to catch his breath, he continued: "The sender ordered me to enter the restroom at exactly 18:10 carrying a key that had been placed for me in advance, but the bag arrived at 18:15. I had to wait inside behind the locked door. As soon as the first person left the bag and walked out, I came out and took what was inside."
The second intermediary continued his testimony: "The sphere was about the size of a football. I placed it inside the water tank (cistern) as instructed. The moment it touched the water, I noticed it began to dissolve slightly… it made a faint fizzing sound. I was terrified. The orders were strict: enter, execute, and leave within five minutes at most. I felt like an invisible eye was watching me, so I closed the tank lid and rushed out."
In the monitoring room, Assistant Lee spoke: "Detective, this confirms the lab report. The material is high-density PVA. The casing was designed to dissolve gradually over ten minutes. That means the head only became visible once the sphere fully dissolved and the contents either overflowed or floated up, which happened exactly at 18:25 when the first witness entered."
Back in the interrogation room, the screen displayed a high-resolution image of the victim Woo Jin's head.
Kim spoke in a low voice, as if reciting a sacred scripture of death: "Despite using an electric saw, the cutting path follows Langer's lines with remarkable precision. This wasn't just mutilation… it was engineering."
He paused for a second, then turned halfway: "The criminal doesn't just have strength—he has knowledge. We're looking for someone familiar with the texture of flesh and bone… a surgeon, or a butcher with the rank of an artist."
On the adjacent screen, the message extracted from the victim's mouth was undergoing spectral analysis.
"Maybe invisible ink? Hidden symbols within the paper?" one officer asked eagerly.
The lab technician replied in frustration: "Nothing. The paper is ordinary, and the ink is available in any store."
The message was stripped of any encryption, which made it even more terrifying:
[You have one week… or you will die]
"He's not trying to hide behind codes," Kim said, staring at the words, "he wants us to understand that he doesn't act randomly." Then he turned to Assistant Lee:
"Everything is connected to the broadcaster Woo Jin.
The woman with the unusual nail…
She may have a connection to the victim, Woo Jin."
Detective Kim raised his head toward the ceiling, closed his eyes, and tilted his head slightly, murmuring as if reconstructing everything in his mind.
Then he said: "The victim Woo Jin's back door opens onto a narrow street. There are no cameras. The neighboring house owner has been away for months. Search for any camera within a one-kilometer radius. There may be a woman who frequently visited Woo Jin's house—she could be the one with the unusual nail… the next victim. The back door may reveal what the front-door cameras of the victim's house failed to capture."