The list that Riku left on Sera’s desk in the Sound Archive Room on Wednesday afternoon was written on the back of a floor-plan printout of Building A, in handwriting that was small and slightly sideways and covered the available space with the efficiency of someone who was used to fitting a lot of information into a small area.

Sera picked it up and read it twice.

On one side: three columns. *Equipment I have.* *Spaces I can access.* *Times I’m available.* The equipment column was longer than she had expected — he had, apparently, accumulated a considerable collection of audio-adjacent tools in the course of his design work, including a directional microphone, a vibration sensor, a low-frequency recorder, and something listed as *sub-bass transducer (portable, experimental, may malfunction).*

The spaces column was more interesting. He had access, through various departmental permissions and what he described parenthetically as *creative interpretation of the visitor policy,* to the pump room under the library, the empty lecture theater in Building D after hours, the loading dock behind the performing arts center where the acoustics were apparently unusual, and the roof of the sports complex, which required a key that he had borrowed from the grounds office three semesters ago and had not yet returned.

The availability column simply said: *Tuesday, Thursday, Saturday. More if needed.*

On the other side of the printout, a single line: *This is not a takeover. It’s a resource offer. You’re in charge.*

Sera set the list down and looked at the waveform on her monitor for a moment.

She had been planning to refuse. This was her plan when she woke up on Wednesday, and her plan through her morning seminar, and her plan through lunch, and her plan until she unfolded the printout and read *sub-bass transducer (portable, experimental, may malfunction)* and found, against her expectation, that she wanted to know what that sounded like.

She did not fold the printout back up. She put it in her notebook.

The problem with working alone, which she had been doing for two years, was not that it was difficult. It was that it was exactly as possible as it was, and she had long since mapped the exact contours of what she could accomplish without help: she could get to any public space on campus at any public hour, she could access the archive room and the equipment available to third-year students, she could record anything that did not require special permission or equipment she did not own. This was sufficient for most purposes.

It was not sufficient for sixty-five sounds in eight weeks.

She had known this when she made the plan at the start of semester. She had made the plan anyway, because the alternative was asking for help, and asking for help meant explaining why she needed it, and explaining why she needed it meant talking about the appointment card in the back of her notebook and the audiologist and the word *progressive* and the way that word sat in her chest like a stone she had learned to breathe around but had not yet learned to put down.

And then Riku Han had run into her with a model and dropped her recorder into a pond and offered her a list.

He had not asked why she needed the sounds. He had not asked why she was in a hurry. He had asked what she needed and made a list of what he had and written *you’re in charge* at the bottom, and the thing about that was —

She picked up her notebook and went to find him.

He was in the Repair Lab, which she now expected, and he was working on his model rebuild, which she also expected, and he had a piece of balsa wood in his teeth and a pencil behind one ear and he did not notice her in the doorway for a moment, which she found — against expectation — easier to deal with than people who noticed her immediately.

“I read the list,” she said.

He took the wood out of his mouth. “And?”

“I want to say some things first.”

“Okay.” He set down what he was working on and turned to face her fully, which she appreciated more than she expected to. Some people half-turned, kept one eye on their work, gave you the impression you were an interruption being managed. He turned all the way.

“I work alone by preference, not by accident,” she said. “If you’re helping me it’s because you have what I need, not because I need company.”

“Understood.”

“I set the schedule and the locations. You show up when I say and you don’t suggest changes to the project itself.”

“Also understood.”

“The rule about talking during recordings is absolute. I don’t care about the reason — if I’m recording, you don’t make sound.”

“I might breathe,” he said.

She looked at him.

“I’ll breathe quietly,” he said.

“And,” she said, “you don’t ask about the project. Why I’m doing it, why I need specific sounds, why I’m in a hurry. None of that.”

A pause. He looked at her with the direct attention she had noticed he applied to things he was thinking carefully about.

“Can I ask about the sounds themselves?” he said. “The acoustic properties. The technical side.”

She considered. “Yes.”

“Can I tell you if I think there’s a better time of day to get a particular sound?”

“Yes, if it’s relevant.”

“Can I—”

“You’re testing the edges,” she said.

“I’m clarifying the terms,” he said. “There’s a difference.”

The corner of her mouth moved. She did not let it go further.

“Four conditions,” she said. “Those four, and we have an arrangement.”

He extended his hand. She had not expected a handshake — it was a very formal gesture for a conversation that had started with him having wood in his teeth — but she shook it. His hand was warm and callused at the base of the fingers from whatever tools he worked with most often.

“Four conditions,” he agreed. “When do we start?”

“Thursday. Two o’clock. The covered walkway between the library and the lecture halls.”

“I’ll bring the directional mic.”

“I know. It’s on the list.”

She left. She had almost reached the door of Building A when she heard him call after her — his voice carrying down the corridor with the easy projection of someone who talked at full volume as a default setting.

“Sera.”

She turned.

He was standing at the top of the basement stairs, one hand on the railing. “The sub-bass transducer on the list. I built it last semester for a project on haptic perception. I never got to test it in a natural acoustic environment. If there’s a location where it would be useful —” He paused. “Just, if you think of one.”

She looked at him.

“I’m not suggesting a change to the project,” he said. “Condition two. I know. I’m just… mentioning.”

She thought about the pump room under the library. The low-frequency hum he had mentioned their first day in the archive room. The specific register of sound that lived below the threshold of ordinary hearing and could only be felt, not heard, in the usual sense.

“Saturday,” she said. “The pump room. Ten o’clock.”

She watched him make the very specific effort not to look pleased about this, and fail slightly.

“Ten o’clock,” he said.

She went out into the afternoon.

On the Blue Stairway going up to the dormitories, she stopped for a moment and looked at the cherry trees. They were at the stage where the blossoms were fully open but had not yet begun to fall, the peak of the thing, the moment that all the photographs were taken because after this it began to go. She raised the secondary recorder and let it run for a minute without moving.

In the background of the recording, if she listened carefully, she would later be able to hear the distant echo of the workshop machinery from Building A, humming at its low constant frequency through the walls and the afternoon and the space between one decision and whatever came next.

She pressed stop and filed the recording and kept walking.

Thirty-seven sounds. Sixty-three remaining.

The arrangement with Riku Han was a tool. A resource. She would use it the way she used every other tool: efficiently, without attachment, and with the understanding that the project was hers and the work was hers and what she was building was something no one else could build, because no one else heard the world quite the way she did.

This was, she thought, both the comfort and the cost of the particular way she moved through things.

She filed that thought the way she filed recordings — labeled, dated, set aside for later consideration when she had more information about what it actually was.

Sumi was awake when Sera got back to the dormitory room, which meant it was either before ten or Sumi had something she wanted to discuss, and since it was seven-thirty the first condition did not narrow things down.

“You look… not different,” Sumi said, looking up from her laptop. “But something is different. Did something happen with the pond boy?”

“His name is Riku Han.”

“The pond boy has a name now.” Sumi swiveled her chair around. “This is a development.”

“He’s going to help with the project. He has equipment and access to spaces I can’t get into independently.” Sera set her bag down and took out the notebook. “It’s a practical arrangement.”

“Obviously,” Sumi said, in the tone she used when she thought something was not obvious at all. “Very practical. He also recovered the recording of your grandmother, which is also very practical.”

Sera opened the notebook and made a note about Thursday’s session without looking up.

“I’m not — I’m just saying, Sera. He went into a pond for you. On the first day of the semester. In clean clothes.”

“He dropped my recorder into the pond.”

“And then he went in to get it.” Sumi paused. “Nobody asked him to.”

Sera wrote: *Thu 2pm — covered walkway — directional mic — possible resonance pool at 3:40pm when building empties.* She underlined *resonance pool* and added a question mark.

“He owes me,” she said.

“Sure,” Sumi said, easily. “And the coffees this morning? He owes you those too?”

Sera looked up.

“I saw the two cups on your desk when I came in to get my phone charger,” Sumi said. “They were from the Building A machine. Which you don’t usually use because you say the coffee tastes like ambition without follow-through.”

“It does taste like that.”

“So someone from Building A brought them to you.” Sumi was smiling in the specific way she smiled when she had arrived at a conclusion and was choosing not to state it directly. “Very practical.”

“Sumi.”

“I’m just observing,” Sumi said. “Observing is allowed. I thought you of all people would respect observation.”

Sera closed the notebook. “I’m going to shower.”

“Of course. Very practical decision.”

She took her things and went to the bathroom and stood under the hot water and thought about the four conditions she had given Riku and the way he had shaken her hand with the gravity of a formal agreement and said *four conditions* back to her like he was filing it somewhere.

The thing was: she was used to being treated carefully. Not unkindly — people were generally not unkind to her, they were careful, they were gentle, they modulated themselves around her in ways that she had come to recognize and had come to dislike with a quiet intensity that she did not discuss with anyone. The careful approach. The slightly raised voice. The over-enunciated words and the concerned checking-in and the way conversations became about her hearing rather than about whatever the conversation was supposed to be about.

She had told one person, two years ago, when she was first diagnosed. A friend from her first year, someone she had trusted. And within a week the careful treatment had started, and she had watched herself become *Sera who has the hearing thing* in her friend’s mind, and she had understood then why she would not be telling anyone else for a long time, possibly ever.

Riku Han did not know.

This was, she understood, not a permanent state. He was perceptive in the specific way of someone who paid close attention to how things worked, and he had already registered something was different about her, she had seen that in his face on the day she had been grasping for sentences in a noisy corridor. He would figure it out eventually, or she would tell him, or —

She turned off the water.

Thursday. The covered walkway. Sixty-three sounds and eight weeks and one practical arrangement that she was going to use efficiently and without attachment and was absolutely not going to think about more than necessary.

She dried her hair and went back to the room and Sumi had, mercifully, moved on to discussing the disaster of the CLB meeting that afternoon, and Sera sat on her bed and listened to Sumi talk and let the ordinary flow of her roommate’s life wash over her like a sound she had not specifically set out to collect but was glad, in passing, to have.

Outside their window, the campus was going quiet for the night.

The cherry trees were very still in the absence of wind.

And somewhere in Building A, she was fairly sure, a light was still on.

Thursday arrived with the particular quality of mornings that knew they were expected.

Sera was at the covered walkway at one fifty-five. Riku arrived at one fifty-eight with the directional microphone in a padded case and a small notebook in his pocket that she had not seen him carry before. He looked slightly less disheveled than usual, which she attributed to the fact that he had presumably not been running.

“Good,” she said.

“Is that a greeting or an assessment?”

“Both.” She looked at the walkway — a covered passage about thirty meters long, connecting the library on the west side to the lecture hall complex on the east. The ceiling was low and slightly arched, made of concrete that had been poured in the seventies and had the particular acoustic density of material that had absorbed a lot of institutional sound over a long time. At either end, the open air. Through the middle, everything that passed between the two buildings: students, occasionally faculty, the specific echo of footsteps and voices and the rolling carts that the library staff used to transport books.

“The resonance is best at three-forty,” she said. “When the lecture hall empties but the library is still in session. There’s about six minutes where foot traffic drops to almost nothing and you can hear the space itself.”

“What does the space sound like?” he asked.

She looked at him.

“That’s a technical question,” he said. “About the acoustic properties.”

She conceded this. “It has a mid-frequency resonance around four hundred hertz. When conditions are right you can hear the building settle — the concrete expanding in the afternoon heat. It sounds like something remembering it was once something else.”

He wrote something in his small notebook. She did not comment on this.

“We have about ninety minutes,” she said. “I want to get the walkway in three different traffic states: full, medium, and empty. The full and medium takes will be background reference. The empty take at three-forty is the one I actually need.”

“Where do you want me?”

“East end. Hold the directional mic toward the center. Don’t move once I start recording.” She looked at him to make sure this landed. “Not at all.”

“Not at all,” he repeated. He looked at the far end of the walkway with the expression of someone calibrating a commitment. Then he nodded and went to take his position.

The next ninety minutes were, in Sera’s experience of the past two years working alone, unusual.

Not in their content — the recording sessions went exactly as she had planned, the traffic states presenting themselves on schedule, the equipment performing as expected. Unusual in their texture. She was accustomed to the specific quality of working alone, which was a kind of self-contained silence, her own attention turned entirely inward toward what she was listening for. Working with another person in the space should have disrupted that.

It did not.

Riku was, as it turned out, genuinely capable of stillness when he chose it. He stood at the east end of the walkway for ninety minutes holding the directional microphone steady, and when students passed through and looked at him curiously he looked back without expression and they moved on, and when she moved to a new position he adjusted to match without her asking, and when she stopped recording and made notes he waited without fidgeting or checking his phone.

She did not know what to do with this information, so she did what she did with most information she did not yet know how to categorize: she recorded it and set it aside.

At three forty-three, the lecture hall emptied.

The walkway went quiet.

She pressed record.

In the six minutes that followed, she heard the walkway settle into itself — the mid-frequency resonance she had described to him, the low four-hundred-hertz presence of the concrete finding its afternoon equilibrium, the small sounds that only existed in the absence of louder ones: a bird somewhere outside the east entrance, the distant murmur of the library, the particular silence between one footfall and the next that was not silence at all but was a kind of breathing.

And, very faintly at the edge of the recording, the slow and steady sound of another person standing still.

She would not use that part. It was incidental, someone else’s presence absorbed into her documentation of a space that was not about anyone in particular. But she would hear it later when she reviewed the take, and she would know without needing to label it whose stillness it was.

At three forty-nine she pressed stop.

“That’s the one,” she said.

He lowered the microphone. He did not ask if it was good or how it had gone. He just nodded and capped the microphone and waited for the next instruction.

Sera looked at the walkway one more time. Then she wrote in her notebook: *sound_039: covered walkway, 3:43pm, empty state, concrete resonance, mid-frequency, afternoon settling.*

Thirty-nine sounds. Sixty-one remaining.

She looked at the number for a moment.

Six weeks and four days of spring. And for the first time since the semester started, she thought it might be enough.