Nam Gijun did not pocket the keys.
He opened his hand. Two rings. One labeled CONNECTING SECTION; the other carrying a yellow tag with its number rubbed away. The empty slot on the board was 04.
“Returned keys go in the drawer for a while,” he said.
“And the ones in your hand?”
“Mine. For my own use.”
Seorin looked between his hand and the empty slot. She did not know enough to identify matching locks from key shapes. Nor could she start trying doors on the strength of a photograph and a memory.
The site staff member asked first.
“You mean there are duplicate keys?”
Gijun nodded.
One answer altered the room’s air. Seorin wrote duplicate key without writing culprit. The external latch could be lowered without a key. Why these keys existed and who had trapped Haeun were still different questions.
“Who had them made?”
“They were here before me. I inherited them from the previous caretaker.”
“Is there a handover record?”
This time he could not immediately point to a drawer.
The staff member asked him to put the keys on the desk. He slid the rings slowly from his palm. Metal struck the edge of the transparent cover with a short sound.
Seorin almost thought it sounded like the latch she had heard by the stairs. Then she stopped. Most metal rang somewhat alike. Connect things as you wished to hear them, and clues would appear anywhere.
Doun opened his phone’s photographs.
The clock comparison from just after their arrival. The key board sat at its edge. Seorin had been watching the monitor; Doun had been trying to frame two clocks together. He had not taken it to count keys.
“Taken at 18:47. We can see an empty slot here. We don’t know how long it had been empty before that.”
She reread the return time.
17:00. COMMON KEY 04 RETURNED.
A contractor’s employee was named in the return field. They had not confirmed who actually wrote the entry or checked the signature. She pointed out the line while the staff member photographed it, without reading the name aloud.
Gijun opened the drawer under close observation.
Rubber bands, batteries, old envelopes.
No Common Key 04.
“Must have put it somewhere else earlier.”
“Do you remember moving it, or are you thinking that because it isn’t here?”
He stared into the drawer for a long time.
“I don’t know now.”
A smaller answer than a found key, but better than a word fitted into the wrong place. She did not record the empty drawer as evidence of theft. The key’s location remained unconfirmed.
Rain thickened outside. Drops struck the gutter below the window. Remembering the rooftop puddles, she added the rainfall to her company’s interim report. Unsorted evidence would not make the building’s hazards wait.
The staff member asked Gijun to list which doors his keys opened. He named the storage compartment inside the connecting section and one exterior entrance. Not the outside latch on the blue door where they had found Haeun.
“That one fastens without a key,” he added.
Seorin waited for him to finish.
“You knew that, but allowed it to be secured without checking for people?”
“People aren’t meant to go in there.”
“Someone was there today.”
His eyes went to the monitor. An empty passage. She did not cover the screen. It now had a note identifying the place and the delay beside it.
He asked whether he could sit. The staff member cleared a chair. The keys stayed on the desk.
“I’m keeping things for former residents. We were told to clear them by a certain date, but some people couldn’t come.”
“Where are they stored?”
“The inner storage compartment in the connecting section.”
She marked one of the two doors he had just named. He said a duplicate could open that compartment. Until someone checked inside, its contents remained unknown.
“Did you record who came?”
“Some people didn’t want to come if we wrote down all their names.”
That might be true. Respecting visitors’ wishes and hiding who had entered would need more material to distinguish. She asked him to explain the collection procedure first, rather than explain other people’s circumstances for them.
He said people described belongings they recognized, and he fetched them. He had obtained collection signatures only a few times. Late at night, they had sometimes used the side door instead of the office entrance.
Doun looked up.
“Continuity of surveillance might have meant covering those hours.”
“A possibility. Not a confirmed purpose yet.”
She was speaking to herself too. She erased an arrow beside the maintenance contract. The moment a story connected convincingly was precisely when caution mattered.
Eungyeong returned. Business Support had sent a photograph of a key handover. She showed the screen before summarizing it in her own words.
A key being handed to the afternoon clearance crew.
Its tag read 04. Part of the office key board appeared behind it. The common-key slot was empty. Another ring hung in the adjacent connecting-section slot.
Gijun looked at the rings on the desk.
Their shapes resembled the one in the picture.
“Is the original photograph available?” the staff member asked.
Eungyeong would ask the sender to preserve it. She added that what she had received might be a copy reduced by the messaging app. Seorin did not begin by writing an afternoon time. They needed to check whether the displayed forwarding time matched the time it was taken.
A worker received a key. The register said it was returned. It was absent from the board now. The caretaker had duplicate keys.
She put each statement on a separate line. Join them in one long sentence, and it became easy to end with someone stole it.
Gijun’s phone rang. He looked at the screen and did not answer. She did not tilt her head to see the caller. She could not know whether he disliked taking private calls here or found this one difficult to answer.
Instead, she returned to his storage procedure.
“Is there a list of uncollected belongings?”
He looked at the envelopes in the drawer.
“A rough one.”
Before taking it out, he asked the staff member’s permission. Seorin checked what she could photograph. Names and contact details were covered; only item numbers and storage locations were visible.
Two small bags. One bundle of cooking utensils. Postal envelopes. Most had the same location.
INSIDE BLOCK 3.
She looked at him.
“The place now called the connecting section?”
“Yes.”
“That’s a little different from saying Block 3 is the west wing.”
He set the paper down.
“We used to call the stairs between them that too.”
She unfolded her plan. They needed a record of whether Block 3 meant an entire building or an everyday name extending into the connection. The names for one place had more duplicates than its keys.
The compartment would stay closed while staff restricted further access. Personnel responsible for verifying keys and preserving evidence would check it together when they arrived. Instead of staying alone to wait, Seorin inspected the safe route to the exit again.
Light caught wet patches below the stairs. Before she understood that the connecting section dropped half a level, it had looked like an especially dark corridor. A single black line on paper contained real doors, stairs, and people.
Metal rattled at the side door.
She stopped and told the staff member beside her where the sound came from. No human shadow showed beyond the door glass. The handle seemed to dip and return. She raised her torch.
“Anyone out there?”
The lower door panel shifted slightly instead of answering. The staff member told her to wait inside the line of the wall, away from the door, and radioed the exterior access staff. Someone checked the rain-soaked passage and reported that a metal sheet at the door’s base was rattling in the wind. No person seen outside.
Seorin checked again. What moved was not the handle, but the gutter’s shadow reflected in the glass. Shift the light, and the reflection slid away. Even something seen needed a second look.
She did not open the door for reassurance. Its locking arrangements, as well as structural safety, were under review. The person outside restricted access to the gutter; inside, they kept the passage clear.
A moment earlier, a palm-sized key had felt like the thing that imprisoned someone. Here were a latch that closed without a key and darkness difficult to pass through without any lock. Choose a key’s owner before checking which door had closed and why, and they could miss the real entrance again.
She marked gutter movement beside the side door on her plan, external latch beside Haeun’s blue door. Different symbols. The things multiplying most easily inside this building were resemblances, rather than rooms.
On the way back, Haeun messaged. Waiting for her ankle examination. Still had the documents.
Seorin told her not to return tonight. Keep the material somewhere safe; submit any necessary parts in a way she agreed to. Then she asked whether an old address had ever said inside Block 3.
No immediate reply.
A typing indicator appeared and vanished. Seorin did not send an impatient question mark. A woman holding her ankle in a hospital chair could not answer every blank in a building. She dimmed her phone and folded the plan while she waited.
The staff member made a custody record distinguishing Gijun’s duplicates from the unlocated common key. Gijun said he could not lock the side door without his key. They would designate the person responsible for the entrances and the keys required. They would not simply take keys away and leave nobody responsible for securing doors.
Only then did Seorin lower her stiff shoulders. They had resolved one small question. An unlisted duplicate existed, and its present custodian was recorded. The missing common key remained missing.
Her phone sounded.
Haeun’s reply. No photograph yet. Three lines of text.
My mother’s mail had a level as well as a block.
Change it to today’s room numbers and the address doesn’t exist.
A letter came to that address this month too.