The data recovery took four days.

Riku did not tell Sera this at the start. He told her he would try, which was true, and that it might take some time, which was also true, and he did not specify how much time because he had learned, through years of working on things that might not work, that specificity about timelines was a form of promise, and promises about recovery were the one category of promise he never made.

On Thursday afternoon he met her at the Repair Lab with the recorder, which had dried sufficiently to attempt a connection. Sera stood inside the door and looked at the lab with the expression of someone doing a rapid and comprehensive inventory.

“You can sit,” he said, moving a stack of circuit diagrams from the second stool.

“I’m fine standing,” she said.

She stood. He connected the recorder to his diagnostic station and began the read. The process was not dramatic — it involved a great deal of waiting and watching percentage bars on a monitor screen — and he was aware of her standing behind him, not moving, not asking questions, which was more distracting in some ways than if she had been asking questions.

“Sixty-three percent of the data is fully intact,” he said, reading off the preliminary results. “Another twenty-two percent is partially degraded but recoverable with processing. Fifteen percent is damaged.”

“The grandmother file,” she said. It was not a question.

“In the damaged fifteen,” he said. “Yes. But damaged doesn’t mean gone. It means I have to work harder to get it.”

She nodded once. Then she said: “I’ll come back,” and left.

He worked on the file for three days. This was not an exaggeration for emotional effect — audio reconstruction at this level was genuinely labor-intensive, a process of mapping corrupted sectors, interpolating missing data from surrounding information, running the result through cleaning algorithms and then listening, actually listening, to determine whether what had been reconstructed was faithful to what had existed. The technical component he could do in his sleep. The listening component required a kind of attention he was not always good at, the stillness and patience of someone waiting for something small and specific.

He found himself getting better at it over the course of those three days.

On Sunday morning he had something. Not everything — the file was still fragmentary at the end, and there was a section in the middle where the reconstruction was his best interpretation rather than a certainty. But there was more than three seconds. There was nearly forty seconds of a voice he had never heard before and would not have recognized as anything but an old woman talking to someone she loved.

He texted Sera: *I have something. Not complete. But something.*

She arrived at the lab within twenty minutes.

This told him something, though he was not sure yet what.

She did not sit when she came in this time either. She stood at the workbench with her hands at her sides and looked at the monitor where the waveform of the reconstructed file was displayed.

“How much?” she asked.

“About forty seconds. The end is still fragmented — I couldn’t get the full sentence she was saying. The beginning and the middle are clean. Clean enough.” He paused. “I can play it if you want. Or I can transfer it to a card and you can listen privately.”

She looked at the waveform.

“Privately,” she said.

“Okay.” He prepared the transfer. He was aware of the specific quality of the silence in the lab while he worked — the fans, the equipment hum, the distant workshop sounds from upstairs — and he was aware of her standing very still behind him, and he thought about what it meant to wait forty seconds to hear someone’s voice again.

He handed her the memory card.

She took it with both hands.

He said: “I’ll go get coffee. There’s a machine on the second floor. Take as long as you need.”

He did not wait for her to respond. He went out and up the stairs and got two coffees from the machine and stood in the second-floor corridor for eleven minutes, watching the light change on the courtyard tiles below, before he went back down.

She was sitting on the second stool when he returned. This was the first time she had sat in the lab. She had her recorder — the secondary one — in her lap and the memory card in her hand and she was looking at the middle distance with the expression of someone who had just received information they were still integrating.

Her eyes were dry. Her face was composed. But there was a quality to the stillness that was different from her usual stillness — softer at the edges, less armored.

He set one of the coffees on the bench beside her without saying anything.

She looked at it. Then she said, very quietly: “Thank you.”

It was two words. They were ordinary words. People said them about coffees and doors held open and small transactions of daily life. He had heard them thousands of times.

These two words were not like the other times.

He sat down on his own stool and drank his coffee and did not ask what her grandmother had been saying, because some things were not his to know until they were offered, and this was not one of the things she was ready to offer.

“How did you know,” she said finally, ‘‘to go get coffee.’’

“I guessed,” he said. “I’m not very good at reading situations usually. But it seemed like the right thing.”

She looked at him. The assessing look she had been using since the pond, the one that filed him into categories he could not see. Then she said: “I need to be somewhere at four. Walk me to the building?”

“Sure,” he said.

They left the lab together and went up the stairs and out into the afternoon, which was doing something specific with the light — the sun had gone behind the cloud bank that came in from the sea most afternoons in early spring, and everything was shadowless and even and softly lit, the kind of afternoon that looked good in photographs and felt even better in person. Sera had her recorder out before they reached the courtyard.

“What are you getting?” he asked, and then remembered. He pressed his lips together.

She glanced at him.

“It’s okay to ask when we’re not recording,” she said. “The rule is for during.”

“Right,” he said. “Sorry. What are you getting?”

“The sound of an overcast afternoon,” she said. “It’s acoustically different from a sunny one. The hard shadows on a sunny day create reflection points — sound bounces differently. On a day like this, sound travels more evenly. Everything sounds a little closer.”

He considered this. “So the cloud cover is actually changing how sound moves.”

“Everything changes how sound moves. Temperature, humidity, wind direction, the presence or absence of reflective surfaces.” She was pressing record now, holding the recorder steady at her side. “Most people don’t hear the difference. They hear more or less the same campus every day and their brain tells them it’s the same. But it’s not. It’s different every single time.”

They walked. He was quiet — actually, genuinely quiet, not performing quiet, because there was something in what she had just said that required sitting with.

Everything changes how sound moves.

He thought about his haptic chamber design and the way vibration traveled through different materials and the way the same frequency felt different in wood versus metal versus fabric. He thought about how he had been designing for people who received the world differently, and how he had been doing it from the outside, imagining what that difference felt like.

He looked at the girl walking beside him.

She was not, he thought, designing anything. She was documenting. She was building an archive of the world as it actually was, sound by sound, before something changed. He did not know yet what that something was. But he had spent enough time around processes of preservation to recognize one when he saw it.

“The file,” he said. “Your grandmother’s. If the end section — the part I couldn’t fully reconstruct — if I run another pass with different parameters, there’s maybe a thirty percent chance I can get more of it. I can’t promise. But I can try.”

She looked at him.

“I know I keep saying I can’t promise,” he said. “I’m not being evasive. I just think it’s important not to promise what you can’t guarantee.”

“I know,” she said. “That’s why I’m not asking you to.”

They reached the door of Building C. She stopped and pressed stop on the recorder and looked at the small screen to review the waveform.

He stood beside her and looked at it too, though he could not read waveforms the way she could. It looked like sound looked: jagged and specific, a particular shape that would never repeat.

“Thursday,” she said. “Two o’clock. The covered walkway between the library and the lecture halls. Bring the directional microphone from your lab if you have one.”

“I have one,” he said.

“Good.” She put the recorder in her bag. Then she said, almost as an afterthought, as if it had just occurred to her: “The recording. What she was saying.”

He waited.

“She was saying my name,” Sera said. “And then something after it. The something after is the part that’s still missing.”

She went inside. He stood at the door for a moment looking at the closed glass, then turned and walked back across the campus in the flat gray light of the overcast afternoon, thinking about a name spoken by someone who was gone, and the sentence that came after it, and the thirty percent chance that it still existed somewhere in the corrupted data of an old recorder that had spent three minutes at the bottom of an ornamental pond.

He walked faster.

He had work to do.

The second pass took two more days.

This was not because the technical work was harder — it was, in some ways, easier the second time, because he knew the file’s structure now, knew where the damage was and where the intact data ended and where the interpolation had to begin. The difficulty was the listening. Running the reconstructed audio through his monitors at low volume, going over the same fragmentary seconds again and again, trying to determine whether the shape of the sound he was building was honest or whether he was constructing something from his own expectations rather than from what was actually there.

This was, he had learned, the central problem of restoration work: the restorer always brought themselves to the material. You could not approach a corrupted file without assumptions about what it should contain. And assumptions, in reconstruction, were the thing most likely to lead you away from the truth of what had been.

He kept that in mind and kept the passes conservative and tried not to want too much from the data.

On Tuesday afternoon he had three additional seconds.

Not a full sentence. Not resolution. Three seconds at the end of the recording where the voice became audible again before fading into noise that was not recoverable. Three seconds in which an old woman said two words and part of a third, the last part cut away by the damage that had not yielded to either pass.

He listened to those three seconds eleven times.

Then he prepared the updated file and texted Sera: *Second pass complete. Three more seconds. Still not the end of the sentence. Come when you’re ready.*

She came the next morning before his nine o’clock. He had not expected her that early — he had been at the bench since seven, working on the rebuilt model, and the knock at the lab door when it came was slightly before eight.

She was wearing the gray cardigan again and carrying two coffees from the campus machine, which she set on the bench without comment. He looked at the coffees and then at her.

“You didn’t have to,” he said.

“You’ve been here since before seven,” she said. “The light in the lab window shows when someone is working.”

He had not known the light showed from outside. He filed that information away and thought about the kind of attention required to notice that.

He transferred the updated file to a new card. She took it and put in her earbuds and stood at the far end of the bench with her eyes closed and he turned back to the model and worked and did not watch her.

He heard, distantly, the campus going about its morning. The workshop starting up above them. Footsteps in the corridor. Someone practicing something on an instrument in the music room on the floor above, the same phrase repeating with the patient determination of someone who was not yet satisfied.

When he heard the small sound she made — not a word, just a brief catch of breath — he did not turn around.

He kept working.

After a few minutes he heard her pull the earbuds out. He heard her set them on the bench. He heard the particular silence of someone composing themselves.

He said, to the model: “There’s more in the last section but it’s below the reconstruction threshold. I can’t get it without inventing it, and inventing it would be wrong.”

“I know,” she said.

“What you have now is real. What you had before was real. The part that’s missing is missing, but the parts that exist — those exist. I didn’t add anything that wasn’t there.”

A pause. Then: “I know.” A different inflection this time. Quieter.

He turned around.

She was looking at the memory card in her palm. The coffee was untouched beside her.

“She was saying,” Sera said slowly, as if testing the words, “‘Sera, listen.’ And then something I can’t hear. And then at the end, in the three seconds you recovered: ‘—always be…’” She stopped.

*Always be.* Two words and a fragment. He thought about what sentences ended with *always be.* He thought about what a grandmother said to a granddaughter in the last summer before a diagnosis, before an ending, in the amber light of a persimmon tree.

He did not say any of his guesses aloud.

“It’s enough,” Sera said quietly. “It’s not everything. But it’s enough.”

She put the memory card in the front pocket of her bag, the small zippered one where she kept the cards she used most often. He noticed this without remarking on it.

She picked up her coffee.

“The covered walkway,” she said. “Thursday is still good for you?”

“Thursday is good,” he said.

“Bring the directional microphone.”

“I will.”

She nodded and drank her coffee and looked around the lab with an expression that was slightly different from the previous times she had looked at it — less like she was cataloguing a foreign country, more like she was recognizing a place she had already been.

“Your model,” she said, nodding at the rebuild on the bench. “The haptic chamber. Is this the same design?”

“Largely. Some adjustments — I found a problem with the floor panel resonance when I was rebuilding. It’s actually better now.”

“So the collision was useful.”

“I wouldn’t go that far,” he said.

The corner of her mouth shifted in the way that he was beginning to learn meant something was happening, something small and internal that did not always make it to the surface. He had catalogued this, without meaning to, the same way she catalogued sounds. The specific movement of a face at the edge of an expression.

“Thursday,” she said, and went to the door.

“Thursday,” he confirmed.

She left. He turned back to the model and the morning and the phrase *always be* and the particular problem of things that existed incomplete but were still, in their incompleteness, real.

He had, he thought, three weeks until the model needed to be finished. Eight weeks until Sera’s project was due. A full semester of Tuesday and Thursday afternoons and Saturday mornings, if she needed them.

Spring at Seiha was eight weeks long.

He had never particularly noticed this before. Now it felt like information.

The directional microphone was in the third drawer of the equipment cabinet, behind a tangle of cables that Riku spent fifteen minutes sorting on Wednesday evening so that Thursday morning would not begin with a search. He tested the battery. He charged the backup. He went through the list of locations Sera had given him — the covered walkway, the pump room under the library, the space between the gymnasium and the arts building where the wind did something unusual when it came in from the sea — and thought about what equipment each location would require.

This was, he recognized, a form of preparation he did not usually do for his own work. His own work tended to begin with whatever was closest and proceed from there through improvisation and iteration. He was not a planner by nature. He was a builder who liked the problem more than the solution because the problem was alive and the solution was just its corpse.

But for this he was making lists.

He sat at his bench Wednesday evening with the list and the sorted cables and the charged microphone and thought about forty seconds of a grandmother’s voice and two words and a fragment, and about a girl who carried a recorder in a canvas bag and had given him two coffees this morning without being asked, and about the way she had put the memory card in the small front pocket, the one for important things.

*Always be…*

Always be what, he thought. Always be here. Always be loved. Always be yourself. Always be brave. Always be the person who notices the sound of an overcast afternoon.

He would probably never know.

But she had the forty seconds, and they were real, and that was what he had been able to give her. He had learned, in his four years of making and repairing things, that what you could give was sometimes very specific and sometimes not what anyone would have chosen, and the measure of whether it mattered was not what it was but whether it was true.

The file was true. The forty seconds were real. The three new seconds at the end — *always be* — those existed, and he had not invented them, and that was the only thing he could control.

He put the microphone back in the bag, already packed for Thursday.

Outside the lab window, the campus was going quiet for the night, the last sounds of the day arriving at intervals: the athletics center lights switching off with a distant clunk, a group of students coming back from the convenience store below the hill, a bicycle bell on the path by the eastern gate.

A bicycle bell.

He thought about sound_031 in Sera’s notebook. The first recording of the semester. He had not been there for it — had been, at that moment, probably still asleep or hurrying through breakfast with the model already threatening to be late — but he could imagine it: the early morning stairway, the light through the cherry trees, the secondhand bicycle whose rider had not yet learned the path.

Sixty-five sounds left. Eight weeks.

He turned off the lab lights and went to get dinner and came back to rebuild and spent three more hours on the floor panels and went to sleep thinking about resonance frequencies and woke up on Thursday ready.