The Registry Wing at midnight was a different building than the one that existed at nine in the morning.

This was not a figure of speech. The structure itself changed character once the scholars had gone and the lamps in the corridors had been turned down to their overnight minimum, leaving only two or three offices where someone had stayed late, small islands of orange light in a hallway that otherwise ran into dark. The sounds changed as well. By day the Wing had a low continuous murmur, footsteps and drawers and the hushed conversation the place seemed to demand. At night there was none of that. There was only the building's own breathing, the small adjustments of old stone cooling, the faint tick of the lamp oil settling in its reservoirs, the sound of a space that had held important things for a very long time and had developed, in Naia's private and entirely unscientific opinion, a kind of disposition toward the work.

She had always thought better at night.

It was a fact she had known about herself for so long that it no longer required examination. After midnight her thinking became less defended and more willing to follow an idea past the point where the evidence thinned and into the territory where the shape of a thing could be felt before it could be proven. She was careful about this. She had rules. No conclusion reached after midnight went onto paper without a daylight review. But the late hours were where she found what she later confirmed in the morning, and so she kept her lamp lit and her curtains open and worked through the hours her colleagues spent on other things.

Lena had left at the tenth bell, as she did on most evenings, pausing at the door with her satchel over one shoulder and the air of a person deciding whether to say something that would be ignored.

"The lamp oil is not unlimited," she had said at last.

"I am aware."

"The senior scholars have a rota for the night lamps. You are not on it."

"Then I will consider myself an unscheduled expense."

Lena had looked at her for a long moment, at the grey volumes and the cold cup of tea and the pen already moving again, and had said, very gently, "Eat something," and gone. The cup of tea was still there. The something had not happened. Naia had noted this as one more small item on a list of items that were not going to be addressed tonight.

Tonight the thing she was working through was the report.

She had spent two days on the revisions. The northern figures had been rebuilt with the correction. The lag between the event and the acceptance of it had been separated out and reported as its own variable, which had made the whole section cleaner and more honest, and which she had done with a reluctance she did not intend to admit to anyone. The clerk intake logs had arrived that afternoon, bound in grey cloth and smelling of the damp basement where the Registry's ordinary records were kept. She had begun to read them at five. It was now a little past midnight, and she had reached the point in the process where the pages stopped being individual pages and began to be a pattern.

The pattern was this. He had been right.

The true onset of the Fading began, on the evidence of the margins, nearly three weeks earlier than her chart had shown. Clerks who had written down what citizens said, I woke up and it was faint, I noticed it last Thursday, it went on the festival night, had unwittingly preserved a second timeline underneath the official one. When she laid the two against each other, the curve she had been so proud of looked like what it was: a smoothed shadow of something sharper, cast by the schedule of an institution.

She had written this at the top of a fresh page in her careful upright hand, and then she had looked at it for some time, and then she had written beneath it, Commander Kairu's observation: confirmed, because the work required that it be recorded, and because the alternative was to pretend the work belonged to her alone.

It did not. That was the strange part. In eight years she had never once minded sharing credit, because she had rarely had anything to share it with. The Wing was a collection of excellent solitary minds. This was something else. It was the experience of being corrected by someone who then helped you build the repair.

She dipped her pen and went on.

She was not expecting footsteps, but she was aware of them before she was aware of being aware. Measured, evenly spaced, with the weight of a person who walked this route regularly and had settled into it. She had a habit of tracking the sounds of the building the way she tracked most patterns: peripherally, continuously, requiring no attention unless something deviated.

These footsteps stopped outside her door.

There was a single knock, so light it might have been a draft. Then, because the knock had produced no response, the door opened.

Commander Kairu stood in the doorway with the dim corridor behind him, which put most of his face in shadow. He looked at her. He looked at the desk, the stacked grey volumes, the lamp, the chair beside the desk that held a second pile of files instead of a coat. He took all of it in at the speed she was beginning to recognize as characteristic, fast and complete and offering no indication of what he made of what he found.

"Scholar Solven."

"Commander." She did not ask why he was there. The Guard's jurisdiction included the Registry Wing, and night patrol was neither unusual nor her business. She went on writing.

He crossed to the window on the far wall and checked the latch, then the second latch below it, then the hinges. He did it the way another man might have checked the time. When he had finished, he stood a moment with his hand resting on the frame.

"It is past midnight," he said.

"Yes."

"You are still working."

"Also yes."

She heard him not leave. It had a distinct sound, a kind of attentive stillness, and she found, to her own mild alarm, that she could hear it from the back of her skull. She finished the sentence she was writing and put a full stop at the end of it with unnecessary firmness.

"You do this regularly," he said. It was not quite a question.

"The Wing is quieter at night. I find it more productive."

"I noticed the lamp from the courtyard. I have noticed it before."

She looked up then. "You have noticed it before."

"Several times in the past year. It is the only lit window in this wing after the eleventh bell." He said it without any particular weight, as a man reported a fact about the terrain. "I assumed someone was being careless with the oil."

"And now you know it is merely me being careless with my sleep."

"I would not use that word."

"Which word would you use?"

He considered it, which was the thing she was coming to find most disarming about him: that he did not answer quickly just to answer. "Persistent," he said.

She went back to her page. She was aware that she had stopped, for a moment, in the way a clock stopped when someone leaned on the case.

He moved away from the window, but not toward the door. He crossed to the wall where her reference shelves stood and looked at their spines with the neutral attention of a man reading a map of a city he did not expect to visit. He did not touch anything. After a moment he went to the window again and stood with his hands behind his back, looking out into the dark, in a posture so similar to the one she herself took when she was thinking that she felt an odd flicker of recognition, as if she had been handed her own coat.

The silence that followed was not uncomfortable. This was notable. Silences with people she did not know well were generally either awkward or aggressively filled. His was neither. It had a quality she could only describe as unclaimed. He seemed to have no particular agenda about it.

She tried to work. She read a clerk's note about a woman in the lower market whose mark had faded during an argument with her sister. She read another about a man who thought he had imagined the change until his dog stopped following him to the door. She read a third, and then she looked up, not at the page, but at the window and the shape of the Tower beyond his shoulder.

It stood in the far dark, where she could always find it. At this hour it was nothing but a pale column over the roofs, its light wan and tired.

"Have you ever seen it bright?" she asked.

She had not intended to ask this. She noted the asking of it, as she noted most things, as a fact to be classified later.

He turned his head slightly, enough to show her his profile. "The Tower?"

"Not like this. Bright. As it would have been at its strength."

He was quiet. She expected a short answer, the kind he gave in meetings, and she waited with the faint pleasure of someone prepared to be unsurprised.

"Once," he said. "When I was eleven. My father brought me to Soleth for the Imperial Review. They lit the Tower for the closing ceremony."

"What was it like?"

He seemed to look inward for a moment, the way a man checked a pocket for something he had not carried in a while. "Like it had made a decision about being there," he said slowly. "Not only present. Certain of its own presence."

Naia sat very still.

It was an extraordinarily exact description. It was better than any she had read in any treatise on the Tower's output, and she had read a great many, all of them reaching for words like radiance and splendor and the glory of the Registry, and none of them had said what she had felt at six years old, in the street by the south gate, with her head tipped back and her father's hand around hers. She had felt that the light was certain. That was it. That was the whole of it. The light had known what it was for.

She pulled her notepad toward her and wrote the phrase in the margin, because the notepad was where she put things she wanted to come back to, and she thought she would want to come back to that.

"I saw it when I was six," she said. "I do not remember the details. I remember the response."

"The response?"

"What it did to me. It was automatic. Like a compass finding north."

He did not say anything for a moment. When he spoke, his voice was lower, and it did not sound like agreement. It sounded like recognition, like a man who had been carrying something without a name and had just been handed the word for it.

"The sense of north," he said.

"Yes."

"That is an accurate description."

They both looked at the Tower through the window. The thin gold spread itself across its stone as far as it would go, pale and effortful in a way the light of her memory had never been. She felt the air of the room change very slightly, as it does when two people are looking at the same thing and know it.

"It has been dimming for six weeks," she said, because the silence was beginning to feel like something she needed to account for. "Every week the Fading counts rise, the Tower's output drops by a measurable degree. I have been charting it. The relationship is too regular to be an accident."

"You believe they are causally connected."

"I believe the correlation is strong. Causation needs a mechanism. I have not found it."

"Not yet."

"Not yet," she agreed, and heard how the words had sounded in her mouth, with a faint, stubborn hope she had not meant to include.

He turned from the window. In the lamplight his face was readable now, which it had not been in the doorway. She had thought of it, in meetings, as a face that did not give anything away. She saw now that this was not quite accurate. It gave away everything, slowly, to anyone willing to look for long enough. It was simply that no one had been looking long enough, and he had never offered to show them how.

"You said that you read the logs this afternoon," he said.

"I did."

"And?"

"You were right." She said it plainly, because the other way of saying it would have cost her more. "The onset began nearly three weeks before my chart indicated. The curve is steeper than I reported."

"I am sorry."

She frowned. "Sorry?"

"It means the court has had less warning than they were told."

"That is my error, not yours."

"It is a shared problem."

She could not have said why that, of all things, sat so strangely in her chest. It was a perfectly ordinary sentence. It was the kind of thing a colleague said. But in eight years in the Wing, no one had ever called one of her problems shared, because no one had ever wanted to hold one.

"Do you know what the name means?" she asked, after a while. She was not sure why she asked. The room had gone quiet again and the question had come from the same place as the question about the Tower, somewhere adjacent to the work. "Auren."

"The place that remembers," he said. "In the old tongue."

"Yes. Most people know that and think no more about it." She turned her pen in her fingers. "I have always found it a peculiar ambition. To name an entire civilization for the act of memory. As if naming it could enforce the fact. As if permanence could be built from a decision to call a thing permanent."

"You think the name is a boast."

"I think it is a hope that has been mistaken for a description." She heard herself and stopped. "That is not an academic position. Please do not repeat it."

"I will not."

He said it so simply that she believed him at once, which was an unfamiliar experience.

"In Kelvari," he said, "there is a saying. The mountain remembers what the village forgets. My father used to say it when the snow melted and we found things that had been lost in the winter. A boot. A tool. Once, a pair of spectacles that belonged to my grandmother's sister, who had been dead eleven years." He was looking at the Tower and not at her. "I thought as a boy that remembering was a kind of holding on. That the empire had named itself for the thing it was most afraid of losing."

"And now?"

"Now I think remembering is only a record." He seemed to hear what he had said, and added, with careful honesty, "I have not thought about it in a long time. I am not certain I believe it."

"It is a good distinction," she said. "A record is not the same as a keeping."

"No."

"The Registry is a record."

"Is it?"

She looked at him, startled, and found that he was looking at her now, and that the question had not been rhetorical. He had asked it as he asked everything, because he wanted the answer.

"That is the question," she said slowly. "That is very nearly the whole of my career. Whether the Registry records what is, or decides what will be. Whether the mark is a report or a command." She stopped. She had not said so much about her work to anyone outside the Wing in years. "I have not found the answer. I am told it is an inappropriate question."

"By whom?"

"By everyone with an office above mine."

"It does not seem inappropriate to me," he said. "It seems like the only question."

She did not reply. The lamp hissed. The Tower stood where it had always stood, a column of tired light. She had the curious sensation of having been agreed with, which was different from being flattered, and different from being approved of, and which she had not felt for so long that she had forgotten it had a texture.

"The supplementary report will be ready by Friday," she said.

"Then you should sleep before Friday."

"I will sleep after Friday."

"That is not a recommendation of mine," he said, "and it is also not a schedule."

"No. It is a decision."

The corner of his mouth moved. It was not quite a smile. It was adjacent to one, a muscle remembering a thing it had been trained out of, and it was gone almost before she had seen it, and she was left with the oddly specific certainty that she had been permitted to witness something by accident.

"Good night, Scholar Solven," he said.

"Good night, Commander."

He went to the door and out into the corridor. She listened to the footsteps move away, even and unhurried, and then she listened to them go on being even and unhurried for much longer than the corridor accounted for, and then there was only the old breathing of the building.

She sat with her hands flat on the desk.

The lamp hissed softly. The Tower stood in the dark beyond the glass. On her notepad, in her own clear handwriting, the phrase glowed pale in the margin, certain of its own presence, and under it she had written nothing else, because there was nothing to add.

She looked at her bandaged wrist. She did not unwrap it. She simply looked, in the absent way her eyes went to things when her mind was occupied elsewhere. The cloth was white and tight and it revealed nothing, and the name beneath it was exactly where it had been for seven years.

It occurred to her that he had been standing by the window, in the dark, for twelve minutes. He had said nine sentences that were not about the work. He had told her something about himself that was not in any register of the palace. And she had told him that she had been six. She had told him what it felt like, in a street by the south gate, with her father's hand around hers.

She had not told anyone that in years.

She took up her pen again.

It took her slightly longer than usual to find her place in the report.