The Fake Envelope

At 18:01, Gang Taejun did not open Door 4.

The door already showed authentication complete. The problem was who had authenticated it. The account name on the screen was blacked out, and the physical card log had come in three seconds late. Go Yura cleared the central network timestamp and lined up the local storage order first.

"The tag is still live. The envelope didn't come out of the printer, it moved from the tray."

"Coordinates."

"Not coordinates. Only the contact sequence survives. The tray, the metal surface inside the door, someone's glove, then open air again."

Gang Taejun didn't chase the envelope. He sealed the authentication log first. I didn't move either. It was because of the condition from chapter 16. The more you wanted to chase a person, the more you had to record first.

At 18:05, Yun Haewon came to Door 4.

He had just come from the security office. His steps weren't fast. But he came straight here. There was no sign of hesitation. Only after he saw the empty tray in front of the door did he notice us.

"What did you put in there."

"Paper."

I said.

"What was written on it."

"Nothing."

Yun Haewon's hand stopped for the first time. His polite expression stayed in place, but his fingertip pressed once against the edge of the tray.

"An input with no content contaminates the decision tree."

"You finally said the words decision tree."

He didn't take the bait.

"This isn't a game."

"That's not something the person who designed a procedure for killing people gets to say."

Gang Taejun stepped between us.

"Both of you, keep it short. Deputy Director Yun Haewon, why can you tell right away when this tray moves."

Yun Haewon didn't answer. Instead he looked inside the tray. There, a tiny trace of silver powder from the tag we'd attached remained. Only after seeing it did he understand that we were tracking movement, not content.

At 18:12, Yun Haewon couldn't return to the deputy director's office.

Gang Taejun took his statement in the corridor. It was an open space. Baek Somyeong stood outside the yellow tape, and Go Yura held her terminal. Yun Haewon checked everyone's position once. He always counts his listeners before he speaks.

"The first authentication at 18:00 changes the order of information."

"Meaning it changes who dies."

I asked.

"The order of information changes a person's choice, and the choice changes the outcome. Beyond that, I can't call it my intention."

"If it's an unintended result, does that lessen your responsibility."

"It doesn't lessen it. But the act of murder and the design of information have to be kept separate."

He was right. That was exactly why I hated hearing it. Yun Haewon was a manipulator, but declaring him the attacker outright would let another hand slip past us. A living victim insisting on the boundaries of his own design was more complicated than a corpse.

Gang Taejun asked.

"Did you know where the fake envelope would go."

"If there's no content, it's normally discarded."

"But it moved."

"That means someone intercepted it before the disposal rule could apply."

For the first time he looked in the same direction as us. Inside the door. The spot where the tray sat empty.

"Who can change the disposal rule."

Gang Taejun asked.

Yun Haewon didn't answer right away. He looked at Go Yura's terminal instead of at me.

"Deputy director authority, director authority, the auditor's temporary authority. And an exception transaction."

"Is the exception transaction Q-13."

"Don't use that name yet."

"I've already seen the watermark."

"A watermark and a function are different things."

He drew a line there. Without stating the function, he admitted a function existed. I wanted to press further. But the fake envelope was on the move right now. The envelope's physical route mattered more than Yun Haewon's knowledge.

Baek Somyeong didn't film the exchange. Gang Taejun hadn't allowed it. Instead she asked out loud.

"Deputy Director, did you make the envelope to save people, or to move them."

Yun Haewon closed his eyes for a moment.

"I believed the two could be kept separate."

That answer was the worst kind of honesty.

At 18:20, Go Yura pulled up the contact sequence in the control room.

The tag wasn't perfect. After the tray came a glove surface, then a metal tray, then fabric. The fabric could have been a coat or a lab coat. The signal skipped twice in the corridor, cut out once, then reconnected.

"Don't treat it like GPS."

Go Yura said first.

"Who said to treat it like that."

Gang Taejun asked.

"I'm the one who wants to."

She named her own temptation first, then trimmed the screen down. Once only the contact sequence remained, a path emerged. Door 4, the corridor in front of the control room, toward the medical office. The account name was still hidden. But the object had gone toward the medical office.

"The priority order changed right before authentication."

Go Yura opened another log.

"The Door 4 tray was first in line, but right before 18:00 the Door 7 authority cut in once. No name shows up. Masked."

Yun Haewon looked at the screen.

"That wasn't done from my terminal."

"Are you asking us to just trust that."

"I'm asking you to verify it."

That sentence resembled my own way of thinking. Disliking it didn't make it wrong.

Go Yura split the log into two lines. One was the physical tag, the other was the authentication priority. The physical tag headed toward the medical office. The authentication priority passed through the Door 7 authority once. The two lines might not belong to the same person.

"Merging them into one would be convenient, but the odds of being wrong go up."

She said.

"Keep them separate."

Gang Taejun answered right away.

Yun Haewon pressed his lips thin at that. His face was the face of a man watching his own design get split apart and dissected. He had said the order of information moves people. Now people had turned that same order of information back on him.

"Who entered the Door 7 access first."

I asked.

"The account name is masked. But the authority format remains. Temporary audit authority."

Go Yura said.

Lee Juwan's name came to mind. But I couldn't write it down just because it came to mind. In my ledger I wrote only "possible temporary audit authority."

At 18:35, the tag signal weakened in front of the medical office.

Oh Sejin was inside the medical office. He was looking at the medication inventory sheet. His right hand wasn't shaking. A hand that didn't shake at all also had to be recorded. Before opening the door, Gang Taejun told Oh Sejin to come outside.

"What's going on."

Oh Sejin's voice sounded like it had rehearsed clinical language.

"We're sealing off access to this room. We're not arresting anyone."

Gang Taejun drew that line first. Only after hearing it did Oh Sejin raise his hands. Once outside the room, he turned out his coat pockets. There was no envelope.

The tag signal was last caught just inside the door. Gang Taejun had Oh Sejin stand against the wall and had me stand outside the door. No solo action. The condition I'd made myself held me back.

Oh Sejin asked, standing against the wall.

"If the medical office is sealed off and a patient needs help, who takes responsibility."

"We're recording the reason for the lockdown right now."

Gang Taejun said.

"A record doesn't save a patient."

He was right. Oh Sejin was a man who used correct statements as a shield. Gang Taejun didn't try to pry the shield away, he simply wrote down the scope.

"Emergency calls permitted. Drawer access requires a witness. No moving cartridges."

Hearing those conditions, Oh Sejin stopped protesting. The absence of protest also had to be recorded. He didn't look like a man trying to guard the drawer. He looked like a man for whom whatever was in the drawer had already been settled.

At 18:42, the medication drawer was opened.

Oh Sejin didn't open it. Gang Taejun put on gloves and opened it himself. Go Yura filmed it. From the gap under the drawer, an empty envelope came out. The paper we had put inside was still folded exactly as before. The tag was stuck to the corner of the envelope. The envelope with no content had made it this far.

Inside the drawer, cartridges of identical shape were lined up. Every label faced outward. Only one faced the wrong way. Its marking had been turned inward.

Gang Taejun didn't pull it out right away. He filmed the whole drawer first, then measured the gaps between the cartridges with a ruler. Go Yura found the pace frustrating but held her tongue. A tedious procedure now cuts down on someone's excuses later.

"Are you asking why it's turned the wrong way."

Oh Sejin said from outside the door.

Gang Taejun answered.

"I'm not asking yet. I'm recording first."

Oh Sejin closed his mouth. If no question comes, no defensive line comes either. That silence left more behind than words would have.

Yun Haewon couldn't see the drawer from outside the medical office door. Gang Taejun had deliberately pushed his position back. Showing a victim his own medication drawer and preserving evidence weren't the same thing. Yun Haewon didn't protest. His hand gripped the armrest of his chair.

I looked at the reversed cartridge and opened my ledger. The reward from chapter 17 wasn't the killer's name, it was a direction. The envelope had come to the medical office. The tag had stopped under the drawer. One object had been placed in backward. All three pointed to the same location.

I didn't say anything right away. The pocket from chapter 5, the fabric from chapter 12, the coat lining from chapter 14 came to mind in order. Objects remember the direction a person absentmindedly corrects them into.

Gang Taejun asked.

"Which one of these is the problem."

"Don't write it down as a problem yet. Only write down what points a different direction."

Oh Sejin didn't look at the drawer from outside the door. The act of not looking lingered longer than looking would have. His right hand, outside his coat pocket, trembled once.

The fake envelope had been under the medication drawer, and only one cartridge among identical ones had been inserted upside down.

Gang Taejun didn't close the drawer. The moment it closed, someone could later claim it had always been that way. He left it open, applied evidence tape as it was, and took four photographs. The front, the top, the label side, and the empty envelope under the drawer.

Oh Sejin didn't watch the whole process through. His gaze kept drifting toward Yun Haewon. Yun Haewon sat in his chair. His face belonged to a man watching emergency supplies with his name on them turn into evidence. To avoid reading too much into that face, I looked at his hand instead. It gripped the armrest, and the tips of his fingernails had gone white.

"How many people know about this drawer."

Gang Taejun asked.

Oh Sejin answered.

"The medical office authority holder, the protected individual himself, and the security chief."

"The protected individual himself."

Yun Haewon said.

"I check the position of the emergency cartridge myself. I have a heart condition."

That statement opened up a new path. It wasn't only Oh Sejin who knew about the drawer. Yun Haewon knew too. So did Gang Taejun, at least on record. Suspicion widened. But a widened suspicion wasn't there to trick the reader, it was there to save us from jumping to conclusions too soon.

Go Yura enlarged the last line of the tag log. The signal cut off under the drawer. There was nothing showing who put it there. Instead, all that remained was a contact interval showing the drawer had stayed shut for seven seconds after it was placed.

"Is seven seconds enough."

When I asked, Oh Sejin's right hand moved slightly.

Gang Taejun watched that hand and said.

"I'm not asking whether it's enough. I'm watching what happens next."

What came next was surveillance of the medical office. The envelope pointed to the medical office, and the drawer held an object facing the wrong way. No hand had been caught yet. So the next chapter was needed.

Surveillance wasn't arrest. Gang Taejun made that difference clear first. Go Yura took the medical office entrance, I took the medication refrigerator, and Gang Taejun took the blind corner of the corridor. Yun Haewon, as the protected party, was seated on the inner bed. That arrangement might have looked strange. The word protection often resembles isolation.

"Are you saying you're using the deputy director as bait."

Yun Haewon asked.

Gang Taejun didn't answer right away. Instead he read out the number on the evidence tape sealing the open drawer.

"I'm recording this precisely so you aren't used as bait. To see who tries to turn your body into a procedure first."

Yun Haewon didn't smile. As the circle of people who knew about the cartridge widened, so did the circle of people who could exploit it. Following only Oh Sejin's right hand would be easy. But the easy line was still too short. We decided to wait at the end of that short line.

The medical office clock read 18:11. Four minutes to the next shift change. Under normal circumstances, this was when Oh Sejin was supposed to sign the medication inventory sheet. Go Yura copied the signature sheet and put the original back in place. We needed to see who picked up the original. Gang Taejun notified the security office not to change the camera angle. Changing the angle might catch more movement, but why it changed would become another question worth suspecting.

Noeul was watching me from behind the doorframe. I wanted to tell the child to hide, but I remembered what his eyes had seen back in chapter 12. If you tell someone who can see not to look, next time they won't tell you anything. So instead, I pointed a finger at my lips, then held up my ledger. It meant he didn't have to speak to help me record.