What the Doctor Changed

19:00, Gang Taejun set the surveillance range of the medical office first.

The camera would not film the patient chart. It would film only the labels on the medicine drawer, Oh Sejin's hands, and the orientation of the cartridge storage. Go Yura covered the top of the screen with a black strip. There were legal reasons and human reasons both. In a room meant to watch over people, opening a person's records carelessly would contaminate the hands searching for the killer too.

"What do you use instead of a warrant."

I asked.

"Prevention of harm on scene, risk of evidence tampering, the deputy director's consent to protection."

"Did Deputy Director Yun Haewon consent."

Yun Haewon was sitting on a chair outside the medical office. He nodded.

"If it's my cartridge, you may look. Just don't disclose the contents."

"We won't look at the contents."

Gang Taejun said. He did not call for Oh Sejin. The medical office was empty and the drawer was closed. A trap must not be forced open by pushing someone in. We had to see whether the person who meant to come in came in on their own.

Go Yura adjusted the camera angle three times. The first caught the label too large. The second caught Oh Sejin's face. Only on the third did only the hand and the drawer remain.

"If you leave out the face, won't it be a problem later to prove who did it."

I asked.

"The entrance camera catches the face. This camera only catches the act."

Gang Taejun answered.

Catching the act and the person separately. The three lines of chapter 20's ledger were already starting to form here. I wrote that remark into the ledger. Writing the person first speeds up hatred, and writing the act first can delay responsibility. Both were needed.

Yun Haewon sat in the waiting room chair. He did not brush off the fact that he was watching over emergency supplies bearing his own name as a joke.

"So my body becomes evidence without my knowing it."

"I'll record that remark too."

Gang Taejun said.

Yun Haewon nodded. He had consented, but he did not look at ease. Even at the moment a victim becomes evidence, the victim's power to choose still shrinks. That cost should not be erased.

20:15, Oh Sejin came into the medical office alone.

He did not close the door. He left it half open. An open door can look like an object claiming innocence. But his hand went to the drawer. He glanced at the inventory sheet once, then opened the second compartment of the drawer.

The normal cartridges had their labels facing outward. Oh Sejin took one out. His hand did not shake. Only after taking it out did his right thumb twitch once. He took out another item of the same shape from inside his coat. The size and color were the same. Only a small scratch on the label was different.

Go Yura held her breath for a long moment. It was clear she was trying not to make a sound.

Oh Sejin inserted the new item. He turned it so the mark would not show. The label faced inward. Before closing the drawer, he lined up the row. He also pushed the fronts of the other cartridges once each with his fingertip. It was too practiced a motion.

He did not look at the swapped item for long. Looking too long leaves a memory. Instead he tidied the surrounding items. He pushed the box of alcohol swabs two centimeters to the right and put an empty tray in the upper compartment. It was the hand of someone flattening a scene under the name of tidying up.

Go Yura said quietly from the next room.

"Take him now?"

Gang Taejun shook his head.

"Wait until he closes the drawer."

"Why."

"The completion of the act and the moment of interruption are different."

He did not use legal terms, but the meaning was clear. The moment the hand takes the item out, the moment it puts it in, and the moment it closes the drawer are each different. Later we would also have to explain exactly where we had intervened.

Oh Sejin closed the drawer. After closing it he pushed the handle once more. It was not that it hadn't closed fully. It was a habit of checking. If that same hand had turned the victim's belongings and the medicine label to face the same direction, the habit could become evidence. Except a habit alone should not be enough to confirm a murder.

I opened the ledger on my wrist. The fact that Yun Haewon's belongings had been in his left pocket. The fibers in the medical office shaft. The scene of Oh Sejin turning the functional side of an item inward after confirming death. Memory and the current footage should not be mixed. I split it into two lines. `Now: cartridge inserted facing the opposite direction.` `Memory: functional side turned inward while arranging the body.`

20:25, Gang Taejun went in.

Oh Sejin had the drawer closed. His hands were empty.

"Step back from the drawer."

"I'm checking the emergency supplies."

"We've confirmed the cartridge was switched."

Color did not drain from Oh Sejin's face. That kind of description is easy to add in later. Instead, he stopped his hand as it was about to reach for his coat pocket. Gang Taejun saw that hand and said it once more.

"Don't put your hand in your pocket."

Oh Sejin raised his hands.

Go Yura came in and put the two cartridges into separate envelopes. A, B. She did not use the words normal and swapped. The function had not been tested yet. Oh Sejin looked at the letters on the envelopes and pressed his lips together.

"It's not lethal."

Gang Taejun asked right away.

"Why bring up lethal first."

Oh Sejin did not answer. The question had caught the clinical language he was trying to hide behind.

Yun Haewon spoke from outside the door.

"That item is mine."

Only then did Oh Sejin look at Yun Haewon.

"It was a measure for the deputy director's safety."

"Safety I know nothing about is whose safety."

Yun Haewon's voice was low. A question asked by a dead victim who is alive weighs more than a document. Oh Sejin did not answer. Gang Taejun pulled Yun Haewon back. If an emotional confrontation runs long, it blurs the evidence.

"The victim's statement will be taken separately."

"Am I a victim, or evidence."

Yun Haewon asked that. This time no one could answer right away.

20:40, two cartridge envelopes sat in the interrogation room.

Oh Sejin did not sit in the chair. He sat only after Gang Taejun told him to. His right hand trembled faintly on his knee.

"Why did you switch it."

Gang Taejun asked.

"To lower the emergency response."

"Whose emergency response."

"Deputy Director Yun's."

"Did you know the outcome."

"An intended outcome and an actual outcome can differ."

He separated intent from outcome. It was a defense typical of Oh Sejin. I wanted to cut that defense off, but Gang Taejun raised his hand first. It meant not to take the order of questioning away from him.

When my turn came I asked only one sentence.

"If we stop this, does Yun Haewon live."

Oh Sejin looked straight at me for the first time. His hand moved before his eyes did. His right thumb pressed against his index finger.

"That question comes too late."

"Too late isn't an answer."

"The swap is one hand."

Gang Taejun stopped his pen.

"One hand?"

Oh Sejin shut his mouth. His face said he had already said too much. But the words were out. One hand. If there's one hand, there's another.

"Who is the other hand."

My question came fast.

Oh Sejin did not look at me.

"That's outside the scope of medical judgment."

"You didn't switch it out of medical judgment in the first place."

His right hand trembled again. This time he couldn't hide it. Gang Taejun raised his hand. If I pushed further, defense would come out before confession did.

"Why you demanded the 2019 records."

Gang Taejun changed the question.

Oh Sejin took a moment to steady his breath.

"The structure was the same back then too."

"What was the same."

"The one who administered treatment and the one who gave the order were different people."

That remark opened the door to chapter 20 early. But no name came out. Gang Taejun did not demand a name. For now he left only the structure.

"Were you the one who administered treatment."

Oh Sejin did not answer. The lack of an answer stayed with us longer than an answer would have.

20:42, Gang Taejun notified him of the arrest procedure.

Oh Sejin did not resist. The moment the handcuffs touched his right hand, the trembling stopped. The stillness was stranger than the tremor had been.

"Don't think this ends here."

"No one said it ended."

Gang Taejun said.

Oh Sejin looked at me.

"Even if you stop that, the correction order still goes out."

The recorder in the interrogation room caught that sentence. Go Yura zoomed in on the screen in the next room.

"What time."

I asked.

Oh Sejin steadied his breath before answering.

"00:07. That one isn't my hand."

That statement was an excuse. It was also, at the same time, the next experimental condition. We had caught the first hand. But Yun Haewon could still die.

Go Yura, in the next room, was already pulling up the 00:07 log reservation screen. He did not look pleased even after hearing Oh Sejin's words.

"Getting it right isn't a good thing."

He said.

"What isn't."

"If 00:07 is correct, then even after we caught the cartridge, it means someone else is going to die."

Everyone in the room fell silent for a moment at that. Deduction is a reward. But when the reward comes at the cost of someone's breath, it's hard to call it only a reward. I wrote in the ledger, `First hand secured. Second hand needs verification.`

The moment the handcuffs clicked shut, the time Oh Sejin had left behind was 00:07.

Before raising Oh Sejin to his feet, Gang Taejun read his rights again. Oh Sejin did not interrupt partway through. With his cuffed hand he was pressing down on his own right wrist. It didn't look like an attempt to hide the trembling, but like an attempt to lock the trembling inside himself.

"Was it 00:07 in 2019 too."

I asked.

Gang Taejun tried to stop me, but Oh Sejin answered first.

"Back then it was thirteen minutes."

The sound in the room thinned out. Thirteen minutes. I knew that number. It was the number from the accident that killed my brother. But what Oh Sejin had said just now was not a full confession. It was one number. If you chase after a single number, the other hands disappear.

"The scope of that statement."

Gang Taejun asked.

Oh Sejin closed his eyes, then opened them.

"Delayed record. Delayed treatment. Delayed responsibility. They're different."

"Is this time different too."

"A swap and an order are different things."

He sounded like someone trying to lessen his own responsibility. At the same time, he was describing the structure of the case precisely. Both could be true at once. I disliked that fact. A clear villain would be easier. Easy conclusions are often wrong.

Go Yura took the cartridge envelopes and walked out. She did not look back at the door. Someone holding evidence should not linger long in an emotional scene. The sound of envelopes A and B going into the security office safe stayed with me colder than Oh Sejin's last words had.

Hearing that sound, Yun Haewon gripped the edge of the bed.

"Are you using my body as an experimental condition."

That question was fair. We had said we would save him, while at the same time watching his body to see whose reaction we were waiting for. Gang Taejun did not make excuses.

"That's why solitary observation is prohibited. The guardian, security, and a recorder watch at the same time. If even one of them is missing, we stop."

"Who enforces that condition."

"If I break it first, Ju Ihyeon records it."

When my name came up I lifted my head. It weighed heavier than being told I was trusted. Trust is a feeling, but a record remains afterward. Gang Taejun had not said he trusted me. Instead he had set me up as the one who would write down his failure.

Oh Sejin was listening to that exchange. With his cuffed hand he touched the rim of a cup. The water barely stirred.

"Even if you block the swap, the correction order still goes out."

He said.

Go Yura stopped in front of the safe. Gang Taejun turned on the control room screen. The next thing to check was not the medicine drawer but the 00:07 reservation screen. Treatment, order, delayed record. When the three words lined up on the same row, even the thirteen minutes from 2019 looked new again. Whether it was time spent waiting for someone to die, or time spent delaying a record after someone had already died, still had to be separated out.

00:07 had not yet come. And yet everyone in the room was already sitting turned toward that hour.

On the control room screen, the reservation list held only three lines. The first line was a routine treatment alert, the second was the security office shift change, and the third was blank. The blank line was more unsettling than the others. Go Yura put her hand over the refresh key but did not press it.

"If you touch it, the trace it leaves behind changes."

She said.

Gang Taejun ordered that Oh Sejin be placed in the isolation room inside the medical office. Outside the door stood not a guardian but a recorder. We were now binding one person's hands while watching to see whether another hand would move. The procedure itself felt cruel. But if we ran ahead without procedure, all that would remain in the next loop was, once again, only feeling.

I wrote on the first line of a new page in the ledger.

`Before 00:07, first hand sealed.`

I left the line beneath it blank. I hoped it would still be blank even after 00:07 had passed. But preparing a blank line in advance was, in itself, an admission that someone might already come to fill it.