Footprints in the Vent

At 08:30, Jeong Mugyeom did not set down his toolbox in front of what I had called the vent.

"It's not a vent."

He said it briefly. Holding a flashlight in his mouth, he wiped the plastic cover of the wall inspection log first. Inside the cover were ventilation check dates and the inspector's name. The last signature was Jeong Mugyeom's, three days ago.

"The section a person can enter is an inspection shaft. It's different from the airway. Put a person in the airway and they die."

Kang Taejun took out the seal tape.

"We film the condition before opening."

"Go ahead. The screws come off top right first. Bottom left first and the metal plate falls."

Instead of answering questions, Jeong Mugyeom gave a sequence. That sequence was more trustworthy than an excuse. He hadn't kept the inspection hatch a secret. The handle was exposed, the lock was old, and the screw heads showed marks from a recent screwdriver.

I looked at the small box under the inspection log. `Infirmary rear, connects to outer calibration room / two person work in emergencies.` On the blueprint it was marked only with a thin line. It wasn't a door. A person could pass through it, but it wasn't a path the residence staff walked every day either.

"Why are you telling us now."

Jeong Mugyeom answered without looking at me.

"If just anyone goes in, more people die."

"Did Deputy Director Yun Haewon go in."

He caught a screw in his palm. His first instinct was not to drop it.

"That's something you say by looking at footprints."

Before opening the inspection hatch, Jeong Mugyeom checked three things around it. Moisture on the floor, the sound of the ventilation fan, whether the infirmary door was locked. He didn't put his hand on the infirmary door handle, only checked the temperature with the back of his hand. It was the motion of someone who knew that touching with fingertips left prints.

"Who normally uses this place."

Kang Taejun asked.

"Me and two facilities staff. On the infirmary side, only Manager Oh Sejin checks it, and only in emergencies."

"What about Deputy Director Yun Haewon."

"She has the authority. She doesn't put her hands on it."

"Does not put her hands on it mean you've never seen her do it."

Only then did Jeong Mugyeom look at me.

"That person opens things with paperwork. She doesn't open things with a screwdriver."

A person who opens with paperwork. A person who opens with a screwdriver. Even facing the same path, their hands were different. If Yun Haewon had come this far, whether alone or let in by someone, she had strayed from her usual method.

At 09:10, the inspection hatch behind the infirmary opened.

The smell inside was closer to wet rubber than dust. Every time the typhoon shook the wall, the wire mesh inside the shaft rang low. Kang Taejun attached a seal number to the inner edge of the entrance and took three photographs. Jeong Mugyeom tied a safety line around my waist.

"Don't go in alone. There's no room to turn around."

"Could someone have gone in alone."

"A thin person can get in. Coming out is different."

He shone the flashlight. The dust on the floor was pressed down in a single line. It was the trace of wet shoes passing through. The left footprint's edge was blurred, while the right footprint kept even the toe and the outer scuff mark. The water hadn't fully dried yet.

Kang Taejun set a small marker beside the print.

"Direction."

Jeong Mugyeom lowered the flashlight.

"From the infirmary toward the calibration room. It's a print going in."

"What about a print coming out."

"It's overlapped, or there isn't one. So I can't say she went there and back alone."

That statement mattered. The path existed. But the existence of a path didn't mean a person had freely gone back and forth on it. The shaft wasn't an answer, it was a constraint.

I noticed a single white thread stuck to the side of the floor. Kang Taejun picked it up with tweezers. The thread wasn't wet. It was a thin, flat fiber.

"Looks like lining fabric."

I said, and Kang Taejun put it in an envelope.

"We don't say what kind of lining yet."

"It looks like the lining of Yun Haewon's key pocket."

"We don't record 'looks like.' We record it after comparison."

He kept to procedure. That procedure frustrated me, but right now that frustration was what kept the case alive.

Jeong Mugyeom swept the flashlight lengthwise beside the print. The footprints weren't a single line. Before and after the dark right footprint were two small water drops. One near the wall, one at the center of the shaft. He pointed at the one near the wall.

"A shoulder must have touched there."

"Whose shoulder."

"The person who went in. Or the person who held onto them."

"Can you tell the two apart."

"I'd need to see the fabric."

He cut off what he couldn't do right away. Instead he did what he could. He lifted the dust near the wall with clear tape and stuck it to an envelope. A tiny amount of white fiber was mixed in there too. Kang Taejun wrote on the envelope: `Wall dust / 09:17.` The time was a number, and a number later removed room for excuses.

At 09:40, the inside of the shaft was enough for one person to crawl through and too narrow for two.

Jeong Mugyeom went first. He used his left hand less. He didn't hide that two of his fingers didn't extend fully. His movements were slow, but his knees never landed on the footprints. I only stepped on the marked side.

The Q-13 key grew lukewarm inside my shirt. This wasn't the first time its temperature had changed as I got closer to the core. I didn't mention that fact. What was needed right now was the shaft. Pulling the key's meaning forward too soon would blur the path.

"It ends there."

Jeong Mugyeom pointed at the wire mesh. It was the exit leading to the outer edge of the calibration room. The mesh could only be released from the inside. There was no handle on the outside. The screws weren't new, and there were no cutting marks.

"You can't come in from outside and leave alone."

"What if someone inside opens it."

"Then it opens."

Kang Taejun asked from behind.

"Does that someone have to be a person inside the calibration room."

"Someone inside, or someone who opened it in advance. It's not automatic."

Jeong Mugyeom said the word automatic like he disliked it. It meant the device didn't decide anything on its own. Someone had to put a hand to it.

Light from the outer edge of the calibration room came through the mesh. The light didn't come in bright. It was a low blue light. On the calibration room floor there was a yellow safety line, and ordinary staff couldn't enter past it. On the first day Yun Haewon died there, I had only looked at the calibration room door. Now I wasn't looking under the door, I was looking inside the wall.

"Could a body be moved through this path."

Kang Taejun asked.

Jeong Mugyeom didn't answer right away. He turned his body halfway. He measured the shaft's width with his own shoulder and pressed the height of the mesh ledge with his palm.

"Hard alone. Even a living person, if they struggle, can't be pulled through. If they're unconscious, you need two people."

"What about the possibility that Deputy Director Yun Haewon moved on her own."

"If only the right leg was fine, she could get in. Getting out, I don't know."

She could get in. Whether she could get out, no one knew. This chapter's answer kept coming out half formed. But when the halves gathered together, the path narrowed.

At 10:20, the cafeteria hadn't started lunch prep yet.

Noeul was wiping cups. I didn't ask out loud. I split my questions across my phone screen.

`Did you see anyone come from the calibration room side that day.`

Noeul shook his head first. Then he pointed at the ceiling speaker with his finger, then pointed at his own ear. It meant he'd missed the announcement. He wrote on paper.

`I couldn't see lip movements. The right side of the face was blocked by a pillar.`

Only after that did he point at the cup shelf. All the cup handles were turned to the right.

`I saw the direction of the cups. Deputy Director Yun Haewon's cup had the handle on the left. It looked like someone set it down in a hurry.`

I wrote the next question.

`What about the shoes.`

Noeul looked at the floor. The cafeteria floor was dry. He lifted one of his own feet, extending only the right one forward. Then he wrote.

`The front of the right shoe was wet. I didn't see the left. It was blocked by the table.`

"What time was it, roughly."

Kang Taejun shaped his mouth slowly without speaking. Noeul watched his mouth, then answered on my phone instead.

`A little before 10:00 by the wall clock. I couldn't hear the central announcement.`

He wrote down what he hadn't seen first. That made what he had seen sharper. I photographed Noeul's sentences exactly as they were. I didn't summarize them.

Noeul thought for a moment, then took a cup off the shelf. He turned the handle to the left, and set another cup beside it with the handle to the right. He looked at the two cups at his own eye level, then wrote.

`A handle on the left sticks out from this spot. Everyone sets them to the right. Only Deputy Director Yun's cup was on the left.`

"Why didn't you say this right away."

Kang Taejun asked. Noeul read his lips about halfway, and after Goh Yura wrote it out again by text, he answered.

`I didn't get a turn in the meeting room. There was no interpreter either. And back then, someone dying mattered more than a cup.`

The sentence was short, which made it linger longer. The person everyone had treated as background remembered the background most precisely. But even he hadn't heard the announcement he hadn't heard. The face he hadn't seen, he hadn't seen. His testimony became evidence only as long as that line was kept.

At 10:50, when we returned to the shaft exit, the right footprint looked even darker.

Jeong Mugyeom brought Yun Haewon's spare shoes. Kang Taejun stopped him from pressing the sole directly against anything, and marked the scuff position on a clear film. There was a small V shaped scuff on the outer edge of the right toe. The same spot was missing from the mud mark on the shaft floor.

"It's a match."

Goh Yura said, zooming in on the screen. She started to attach a technical term, then stopped.

"So, it's like it's stamped. The right foot."

"What about the left."

"It's blurred. Either the foot was dragged, someone held it, or it touched the ground for a short time."

Three possibilities remained. Yun Haewon might have gone in on her own. Someone might have dragged her in. Someone might have been waiting inside. A single footprint shouldn't narrow down the suspects.

At 11:05, Kang Taejun stopped again beneath the exit ledge.

He picked up one more white fiber from among the dust. This one was wet. A fiber holding water was stuck to the metal ledge. I thought of the pocket where Yun Haewon's key had been found on her body. The left pants pocket. That pocket, different from her usual habit.

"Her belongings might have fallen out here."

Kang Taejun looked at me.

"It's a possibility."

"Can we call it likely."

"Not yet. Whether the key fell out, whether only the pocket lining touched something, or whether someone moved it, those are different things."

He listed three. Fell out. Touched. Moved. Once the words were separated, the case separated with them.

Jeong Mugyeom locked the inside of the shaft again. Noeul's text messages, the footprint photos, and the fiber envelope all went into the same evidence box. I took the Q-13 key out from under my shirt. The metal was still lukewarm.

Kang Taejun asked.

"Are you recording the key too."

"Yes. But I'm not putting it into the conclusion right now."

He nodded. It wasn't trust. It meant the procedure was pointing in the same direction.

Goh Yura held the fiber envelope and looked toward the cafeteria once more.

"If we line it up with Noeul's testimony, the deputy director's right foot got wet after she passed through the cafeteria, at the earliest. Cup on the left, right foot wet, right footprint in the shaft. That's the order it comes out to."

"What's missing from that order."

Kang Taejun asked.

"Why it got wet. Who opened it for her. Why the left footprint is blurred."

Goh Yura folded down three fingers. There were more blanks than answers, but the blanks were positioned more narrowly than before.

Noeul wrote his last sentence on his phone screen and held it out.

`What I saw was only the right foot. Don't use the left.`

He was guarding against his own testimony growing larger than it should. I photographed that sentence. It's rare for a witness to write down their own limits. Rare things should be treasured.

Jeong Mugyeom attached a new seal to the inside of the inspection hatch last. This time, he wrote his own name beside Kang Taejun's signature. After finishing his name, he paused once.

"I didn't write this down before."

"What."

"That I kept people from remembering this shaft. It should have been sealed off after the accident, but if I sealed it, there'd be no other way out, so I left it."

"Was another way out necessary."

"There always has to be a way to get people out."

That statement was true. Which made it dangerous. A path for getting people out is also a path for putting people in. Jeong Mugyeom knew that. Knowing it, he still hadn't closed it off. The fact that protection and concealment could be tightened by the same screw stayed behind in front of the inspection hatch.

The wet right shoe print at the end of the shaft matched the scuff on Yun Haewon's sole. The footprint didn't open a path. Instead, it left behind only the fact that the person who had entered that path was Yun Haewon, narrowed down too tightly to escape.

There was only one next question. Why had Yun Haewon gone in. Before I could hear that answer, this time, I had to pull him out first.