Maren woke to the sound of someone breathing, and it took her a full minute to understand that it was the sea.

In, for a slow count of ten. Out, for a slow count of ten. It was too regular to be natural and too large to be anything else, a vast steady respiration that came through the walls and the floor and the bed frame itself, and underneath it, at the end of every long exhale, a single low bell-note that she felt in her breastbone before she heard it. She lay with her eyes shut and counted three full cycles before she let herself open them.

Stone. A curved ceiling of pale stone blocks, fitted so closely that no mortar showed, rising to a shallow dome. A round room, perhaps four paces across, with a narrow window cut deep into a wall at least an arm's length thick. A bed of rough linen and heavy wool that smelled of smoke and cedar and salt. A three-legged stool. A hook on the wall, and on the hook, her own sweater, stiff as cardboard, hung out to dry like a flag of surrender.

She was wearing a man's shirt. It was grey, soft with washing, and it came to the middle of her thighs. She decided, firmly, to think about that later.

She sat up, which was a mistake, and waited for the room to stop swinging. Everything ached, in the dull, thorough way of a body that had been thrown against the sea. Her hands lay on the blanket in front of her, wrapped to the wrist in clean linen strips. She turned them over. The knots were small and square and had been pulled to exactly the right tension, snug without strangling the fingers, the way you tied off a repair so it could breathe.

One-handed, she thought, absurdly, and could not have said why.

Then she saw the table by the window and forgot everything else.

The book lay open on a board, and someone had interleaved it. Sheets of rough grey blotting paper between every wet leaf, a row of smooth sea-stones set along the edge of the board to hold the weight without crushing the cockled paper. The cover had been propped on a wedge of folded linen to let air reach the spine. It was precisely, almost insultingly, what she would have done herself, and she had not asked anyone to do it.

Maren got out of bed with the blanket around her shoulders and crossed the cold floor in three steps. The ink on the open page had settled into plain, ordinary handwriting. Low water. Count the pages twice. It lay quiet under its stones, like something sleeping with one eye shut.

"Who taught you that?" she said aloud, to whoever had done it.

The room had no opinions. Her coat hung on a second hook, and when she fished in its pocket her fingers closed on her phone, a cold black rectangle with a crack across one corner. She pressed the button. Pressed it again. Held it down for a full ten-count, the way you did for a stubborn computer, and stared at a screen that showed her a very small, very tired woman with salt in her hair.

"Great," she said. "It's a very expensive coaster."

A knock came at the door: two soft raps, spaced, patient.

She waited. The knock did not repeat. After a long moment she understood that the person on the other side would wait there until she spoke, and that this was a form of courtesy.

"Come in," she said.

Tavian Orrel opened the door and did not enter. In daylight he was both more and less than she had thought: taller, and younger, and more exhausted, with the kind of face that would have been merely handsome if it had been allowed to move. He wore a different coat, the same dark cut, the same high collar. The grey glove was back on his left hand. In his right he carried a tray with two cups and a loaf of dark bread, and he held it with the care of a man who did not trust the floor to stay where it was.

"You slept nineteen hours," he said.

"Nineteen."

"It is the afternoon of the following day."

"Right. Of course." She held up her bandaged hands. "You did these."

"Yes."

"They're good knots."

"I have had practice." He set the tray down on the stool, at the farthest point from her that the room allowed, and straightened. "You should eat. And then I should tell you where you are, and what that means. It will not take long. I have found it is better done plainly."

She pulled the blanket tighter. "Go ahead."

He told her the way she imagined he told everything: in order, without adjectives, like entries in a record book.

The islands were called Halvane. There were seven of them, spread across a sea with no other land in it that anyone had ever found. She was on the largest, a place called Orrel's Rest, in a tower where the tide was kept. The water here did not belong to the moon or the wind or any natural law she would recognize; it kept its time by a different arrangement, and he was the person charged with seeing that it did. He said this without any particular emphasis, as if he were telling her the price of salt.

The door she had come through was called the Hollow Shallows. It opened four times a year, at the turning of the season, when the sea went white and still from shore to horizon and the islanders called it a Blank Tide. It did not stay open long. Nothing else could open it. Nothing else ever had.

"Until you," said Tavian.

"Why?"

"I do not know." His eyes held steady on hers, and it was true, as far as it went; she had no way of knowing how far that was. "I know only that the next Blank Tide is eighty-four days from today. Until then there is no road back."

"Eighty-four." She said it again, quietly, testing its weight. "Days."

"Yes."

"Okay. Okay, that's..." She heard her own voice go thin and bright, the voice she used on clients who wanted a water-stained family bible restored by Tuesday. "That's actually a real problem, because I have a hymnal due on Friday. A nineteenth-century hymnal, with a very difficult spine. My landlord has a roof inspector coming on Thursday. I have a reservation at a noodle place on Sunday that I booked six weeks ago, and they are extremely strict about cancellations, and no one is going to..."

She stopped.

No one was going to ring anyone. That was the fact under all the others. There was a landlord who sent cheerful texts, and a handful of clients, and an old master who had retired to the coast and sent her a card each winter. There was no one who would notice by Thursday that she had not come down the stairs.

"I am sorry," Tavian said.

"Don't." It came out sharper than she meant. "Sorry is what people say when they can't fix it."

"Then I will not say it."

It was so dry, and so unexpected, that she laughed. It was an awful laugh, cracked down the middle, and it went on a second too long and turned into something else. She pressed the heel of one bandaged hand against her mouth.

"I'm a paper conservator," she said, once she could. "I mend books. I fix other people's disasters. I am not a person things like this happen to."

"Conservator." He said the word slowly, the way a man tests an unfamiliar tool in his hand. "What is that?"

"I make old, broken paper last longer. Without making it new."

Something moved behind his eyes, there and gone, faster than she could read it. His face did not change, but he went completely still, the way a bird goes still when a shadow crosses the grass.

"Without making it new," he repeated.

"That's the whole job. You don't replace what's there. You keep it, and you help it hold."

He did not answer. He crossed the room, then, for the first time, three steps, close enough that she could see the weave of his coat and the fine lines at the corners of his eyes, and lifted a cup from the tray and held it out. He did not hold it at arm's length this time. When her bandaged fingers closed around it, his bare hand remained under hers for the length of a breath, steadying, before he drew back.

"Drink," he said.

It was hot, and sweet, and faintly bitter, and it went down like a hand pressed flat between her shoulder blades. She drank all of it. Her breathing slowly learned its way back to the pattern of the sea outside the window, in for ten, out for ten, and the room stopped pitching.

"Thank you," she said.

"Do not thank me yet." He said it quietly. "There is the island to meet. They will have heard by now."

They had.

By the time Maren could stand without leaning on the wall, a low murmur was rising from somewhere beneath the tower, the sound of many people trying to be quiet and not succeeding. It was the custom, Tavian told her: when the Shallows opened, the island came to look. It was a courtesy as much as a curiosity. She was welcome to refuse.

"If I'm going to be looked at," said Maren, pulling her stiff sweater back on over his shirt, "I'd rather do it standing up."

He studied her for a moment, and something that might have been approval, or surprise, crossed his face and was put away. "This way."

The stairs wound down through the heart of the tower in a tight stone spiral, every step worn to a shallow dish by centuries of feet. Cold air rose to meet them. Near the bottom, Maren passed a doorway that stood ajar on a vast, dim room, and glimpsed what looked like hundreds of pale rectangles hanging in dark water, quivering faintly, like a school of fish held in suspension. She slowed. Tavian's hand came up, not touching her, only interposing, and he drew the door closed with two fingers.

"Not yet," he said.

She let it go. For now.

Outside, the afternoon was grey and bright and enormous. The tower stood on a spur of black rock above a small harbor, and below it a path of crushed shell ran down between low, whitewashed houses with turf on their roofs and nets spread across their walls. A line of white stones had been laid across the path, perhaps thirty paces from the tower door. Beyond it, in a loose, quiet crescent, the island was waiting.

There were perhaps forty of them. Fishers in oilcloth. Women with baskets on their hips. A pair of old men sharing a pipe. Children in clusters, held back by the shoulders. Weathered faces, wool and salt and sun, not hostile, not anything she could name, only intent. They looked at her the way she looked at a document that arrived in a shoebox: with respect, and with a clear, practical sense of how long it would last.

A whisper began somewhere at the back and ran forward through the crowd like wind through grass.

Tide-washed.

She heard it again, and again, in different mouths. Not unkind. Gentle, even, in the way people speak of the dead. A little girl near the front, perhaps six, tugged at her mother's skirt and asked, in a clear carrying voice, "Is she going to stay?"

The mother's hand came down over her daughter's hair. "No, love," she said, quite kindly. "They don't."

Maren had been called many things. Careful. Meticulous. Difficult. Once, by an ex who had meant it as a diagnosis, a closed door with a very nice finish. She had never been called a person who would leave, and it struck her in the one place she had not had time to armor, so fast and so clean that for a moment she could not breathe. She had spent sixteen years being the one who stayed: at the bench, in the same flat, in the same careful orbit. And a whole island had just looked at her once and decided that she was exactly the kind of person who would go.

A broad shape came pushing through the crowd, scattering fishers like gulls.

She was a big woman, built along the lines of a stone wall, with forearms like rope and iron-grey hair braided down her back and an apron that had seen a great many fish. She carried a loaf wrapped in a cloth. She stopped at the line of white stones, dipped her chin briefly to Tavian, "Warden," and then turned her whole frank attention on Maren. It was the look of someone sizing up a fish she had every intention of being kind to.

"Odda Brask," the woman said. "I sell the fish."

"Maren Ilves. I sell nothing, apparently. I'm just here."

Odda's mouth twitched. She held out the loaf, at arm's length, and did not step over the stones. After a moment Maren crossed the line to take it. It was warm through the cloth, dense with salt fish and seaweed and something sharp and green.

"Eat all of that," said Odda. "You'll want your strength."

"For what?"

"For the leaving."

The crowd had gone quiet enough that Maren could hear the tide-bell sounding far below in the rock.

"I haven't decided to leave," she said.

Something crossed the older woman's face then, so quick and so tired that it might have been a trick of the shifting grey light. Her voice, when it came, was gentler than her forearms. "No one ever has, love," said Odda Brask. "It comes on them anyhow."

"That is enough," Tavian said.

He had not raised his voice. He had not moved. But the crowd shifted, the way a flock turns, and the little murmurs folded back on themselves. "She has come a long way, and she has not eaten. You have seen her. Let her be."

They went, in ones and twos, with backward glances. Odda lingered a moment longer, her small sharp eyes moving between the Warden and the woman in his borrowed shirt, and said, very low, so that Maren had to strain to catch it, "You've told her, then."

"I have told her the days."

"Hm," said Odda, in a tone that held an entire argument, and went down the shell path with her back like a wall.

Maren stood with the warm loaf in her bandaged hands and the sea wind in her hair, and for a while she did not trust herself to speak.

It was Tavian who did not break the silence. He walked her back up the stairs and left her at her door, and she let him go three steps before she said what had been circling her skull since the rocks.

"Why did you look at my book like that?"

He stopped. His back was to her. "Like what?"

"Like it had said your name."

The sea breathed in, through the old stone. He turned around slowly, and his face was as smooth as the first page of an unused book.

"The ink answered the water," he said. "Ink does not do that. In my work I have seen ink do a great many things, Miss Ilves, and I have never seen it do that. I wish to know why."

It was a perfectly reasonable answer. It was also, she noticed, the answer to a different question. He had not been looking at the ink. He had been looking at the handwriting: at its slant, at the hook on every descender, at the particular way each letter reached for the next. She knew the difference. It was her entire profession, the difference between what a surface said and what had been put there by a hand.

"That's all?" she said.

"That is what I can tell you."

She could have pushed. She had the right, and the anger, and nineteen hours of sleep behind it. But she was standing in a stranger's tower at the bottom of the world with a book she had not yet worked up the courage to read, and she had spent twelve years learning that you did not force a binding open when it was already cracked. You waited. You watched where it wanted to give.

"All right," she said.

He inclined his head, and she saw him register that it was not agreement.

Supper was served in a long, low kitchen at the base of the tower, at a table that could have seated twelve and was set for two, one place at each end. A stew of fish and barley and something that tasted like green smoke. Brown bread. A candle in a dish. The silence was not hostile, exactly. It was the silence of two people each standing guard at a door, and each pretending that the other did not have a key.

Tavian ate like a man doing sums: small, measured bites, his eyes on the middle distance, his bare hand moving without appetite from bowl to mouth. The grey glove stayed on the table beside him. He left half of what he had been given. Maren, who had not eaten in nineteen hours and could not have said what she tasted, pushed a piece of fish around her bowl and counted the cycles of the sea. In. Out. In. Out. The candle flame leaned and straightened with it, as though the whole room were a lung.

"The bell," she said at last. "At the end of each breath. What is it?"

"The tide." He did not look up. "Marking its place."

That was all he gave her, and she let it be.

She did not sleep.

She lay in the round room with her face to the dome and listened to the sea breathe and the bell sound, and thought about a hymnal on a bench in a city that was no longer under her feet; and about a woman who had hummed over broken cups; and about a small girl asking, in her clear carrying voice, is she going to stay. Around what must have been midnight, she gave up and got out of bed.

The tower was not quiet at night. It creaked, and settled, and exhaled draughts from places that did not seem to have windows. She followed the bell. Up, not down: a narrow stair she had not noticed, curving past her own door into the dark, ending at a low arch where a door had been left a hand's width open and a thin ribbon of cold air threaded through.

She stopped on the last step.

Beyond the door was a stone balcony, hung out over the black water. There was no moon she could see, only a scatter of hard bright stars and, below them, a faint pale shimmer on the sea, as though the water had swallowed a piece of the dawn and was keeping it for later. Tavian stood at the rail with his back to her. He had pushed his sleeve to the elbow. The grey glove lay folded on the stone beside him.

His left hand was held out over the water, palm down, fingers spread, the way you hold a hand over a stove to judge the heat.

And along the inside of that wrist, from the heel of the palm up under the cuff of his shirt, ran a line of black.

It was thin as a hair and straight as a crack in porcelain, and it lay under his skin the way ink lies under tissue. She knew ink. She knew exactly how it bled and wicked and spread, and she knew that this was not a bruise and not a scar and not a vein, because as the tide-bell sounded, far below, a long soft note in the stone, the line crept. It moved an inch, perhaps less. Just enough to be certain.

He did not flinch. He did not even breathe differently. He only stood there, with his hand over the pale water, like a man taking a pulse he had long since stopped hoping would change.

Maren did not make a sound. She went back down the stairs on silent feet, one hand flat against the cold wall, and lay awake until the window turned grey, thinking of a hand held out over a dark sea and a line of ink where no ink should be, and of a tide that kept its time by something other than the moon.