Marco had the name by Tuesday morning, and he carried it into the library like a man carrying a full cup across a ballroom.

He had been up all night. It showed in the creases of his coat and the gray hollows under his eyes, but he stood very straight at the end of the long table with a folder in his hands and made his report in the level voice he might have used to read out a tide table. The gray car had a dealer's sticker on the rear glass, half scraped away. Gavin, who had photographed it from the roof of the bonded shed with a long lens and endless patience, had made out the last three letters of the stamp. A dealership in Kestrel Basin, at the northern end of the harbor. A sale eighteen months ago, for cash, to a man named Tobias Marl.

"Marl," Matteo said slowly.

"Thirty-eight. He drove for us on the north docks until two years ago, when he was dismissed for drinking on a shift." Marco turned a page. "Since then, odd jobs. Hauling scrap, mending nets. He keeps a room over a chandler's shop. He hasn't slept in it since the night of the fire."

Sienna sat at her place with the blue notebook open in front of her and a cup of salted coffee she had not touched. Beyond the long window the sky had gone the color of a healing bruise, low and yellowish, with a wind in it that bent the cypresses all one way. The green leather notebook from the gala lay on the table beside Marco's folder, where he had set it down like something he was glad to be rid of.

"And that?" she said.

"I've had it apart, miss." His broad calm face did not change. "The leather, the lining, the clasp, the paper. A man at the university put it under a lamp for me last night and tried three solvents on a corner of the endpaper. There's no transmitter in it. There's nothing on the pages." He paused. "It is a notebook."

"Which is worse," said Sienna.

"Yes, miss. I thought so too."

Matteo had not looked up from the photograph of Marl, a thin sandy man in a donkey jacket, squinting against the sun. When he spoke, it was in the voice she had learned to dread, the quiet even one that meant a decision had been made somewhere out of her sight.

"Marco, how long to find him?"

"A day. Two, if he's gone to ground."

"Then I would like her out of this house until you have."

Sienna put down her pen. "I'm sorry?"

"There is a lodge." He still did not look at her. "Harrow's Rise, in the hills behind the city. My grandfather built it for hunting, and my father used it for the kind of conversations he did not want overheard. It is forty minutes by the old road. It has no telephone, one track in, and a view of every approach for half a mile. The only people who know it exists are Marco, Mrs. Venn, and me." A pause. "I would feel a great deal better if you were there while Marco's men turn over Kestrel Basin."

"And you?"

"I'll be here."

"Alone, in a house with a gray car at the end of the garden."

"Sienna."

"No." She stood. She did not raise her voice; she had learned from him that it was not necessary. "I'll go to the lodge if there is a reason to. I'm not a fool. But I won't be put in a box on a hill while you stay down here as bait. If I go, you go. One night, and Marco sends word in the morning. That is my condition. Call it clause seven, if you like."

Marco, at the end of the table, became deeply interested in the folder.

Matteo looked at her at last. She watched the struggle cross his face, the old instinct to lock every door in the world and station himself on the outside of it, and she watched it lose. He had written a rule on a blackboard that said they did not decide for each other. He drew a long breath.

"One night," he said.

"One night."

"I'll tell Mrs. Venn to pack a hamper."

"I'll watch her do it," said Sienna.

They left at three in the gardener's old estate car, because no one watching the villa would look twice at it. Matteo drove. His right hand, in its lighter dressing, rested on the wheel with a care she noticed and did not mention, and he took the first bends like a man who had learned them at fifteen and never since needed to think. The city fell away behind them. The road climbed through pine woods, switchback after switchback, the trunks standing black and wet on either side and the light thickening to a dull copper dusk. Somewhere past the third bend, thin gray sleet began to tick against the windscreen.

She watched him in profile. He had stopped looking at the mirror around the second switchback. He had the stillness of a man for whom the road behind him was finally empty, and she let herself, just for a moment, enjoy it.

The lodge sat under an overhang of rock at the end of a track that was barely wide enough for the car. It was long and low, built of gray stone and dark timber, with a deep porch and a stack of split logs against one wall that reached nearly to the eaves. A single window showed, small and square, with a shutter hanging askew. Behind it the hill went up in a slope of black pine into cloud. Below, through a gap in the trees, she could see a long way down: a scrap of far gray sea, a handful of yellow lights, and the whole bruised sky pressing the world flat.

"It isn't much," said Matteo.

"It's perfect," said Sienna, and was surprised to find that she meant it.

Inside, it smelled of cold ash and old pine and a faint sweetness of apples. There was one great room with a floor of worn flagstones, a table for six, two armchairs and a long sagging sofa drawn up before a fireplace you could have stood in. A barometer hung by the door. A shelf of paper-backed books leaned against the wall, swollen with damp. At the back, through an arch, lay a kitchen with an iron stove, and beyond it, down a short passage, two narrow doors.

He opened the first and stood quite still.

A bucket sat in the middle of the floor. Above it a dark stain bloomed across the ceiling plaster, and a steady drip, drip, drip fell into the tin with a sound like a patient clock. A slate had gone in the last gale, plainly, and no one had come to mend it.

"The caretaker was to have been up in October," Matteo said, to the bucket. "I'm afraid I forgot to remind him."

He opened the second door.

It was a small square room with whitewashed walls and a single window. It held a washstand, a peg rail, a rag rug and one bed. It was a narrow double, iron-framed, with a faded patchwork quilt, and it stood against the far wall as bare and respectable as a church pew.

There was a pause.

"I'll take the chair," said Matteo.

"I haven't said anything."

"You've done something with your face."

She had. She was fairly sure of it. She closed the door on the leaking room and crossed the rag rug and began, without comment, to strip the bed. She lifted the quilt and shook it out. She lifted the mattress, one edge at a time, and ran her hand along the slats beneath and into the corners of the frame. She tried the window latch, and knelt to look under the washstand, and opened every drawer with a quick flat thumb.

"You're searching a bed," said Matteo from the doorway.

"I'm searching a room."

"For what?"

"I'll tell you when I find it." She sat back on her heels. "Nothing. It's clean. It's merely small."

He was leaning against the frame with his arms folded and his bandaged hand tucked in, and there was something in his face that she had not seen for a long time. It was humor, plain and tired and warm, as though she had said something that had gone straight into a place he kept shut. "You look like a customs officer," he said.

"I'm a very good one."

"I know." He cleared his throat. "The bed is yours. I'll sit by the fire."

"No."

"Sienna."

"You'll sit by the fire for ten hours with your eyes open and call it sleeping." She stood and shook the dust from her skirt. "That isn't sleep. It's a vigil. You've been keeping one since the first of September, and Mrs. Venn has told me about the study sofa."

"Mrs. Venn is a gossip."

"Mrs. Venn is a saint who says exactly what she sees. Rule two, Matteo. In private we do not perform. That includes martyrdom."

"It is not a performance."

"It's the most performed thing I have ever seen."

He opened his mouth, and shut it again, and a dark flush began to climb out of his collar. She watched it with deep and unworthy satisfaction. "You can't sleep in a chair," she said, more gently. "And I can't sleep in a bed while you sit in a chair outside the door like a dog at a grave. So I propose that neither of us does. I'll take my blankets to the fire. You may do as you like."

"I would much prefer..."

"I know what you would prefer," said Sienna. "I am telling you what I am doing."

There was a long silence in the small white room. The bucket dripped faintly through the wall. And then, very slowly, his mouth began to curve. It was not the wry half smile or the courteous one. It was the wide helpless smile of the gala, the one that got out without permission.

"Mrs. Venn," said Matteo, "is going to be insufferable."

The hamper, when she unpacked it on the kitchen table, was a small masterpiece of forty-one years' practice. There was a loaf wrapped in a cloth, a round of hard yellow cheese, a cold roast chicken in greaseproof paper, a flask of soup still faintly warm, a jar of apricot jam, a tin of biscuits, and at the very bottom, wrapped in tissue like a jewel, a single green-gold pear. A piece of card was tucked into the paper. The handwriting was square and firm. For emergencies. V.

Sienna tested the chicken, and the soup, and the cheese, and the bread, while Matteo watched from the end of the table and did not say a word. She cut the pear in two with his penknife, and held half out to him across the cloth.

"Eleven pears," he said gravely, "in that kitchen. I have never once been allowed to eat one."

"This isn't one of the eleven. It's an emergency."

"I believe it is." He took it. Their fingers did not touch. He bit into it with an expression of such absurd and reverent attention that she had to turn away and busy herself with the stove.

By seven the sleet had turned to snow.

It came on all at once, as it does in the hills, thick and soft and silent, filling the window with a slow gray swirl until the pines had gone and the world was a small warm room with a fire in it. The wind rose behind it. It moaned along the roof, and rattled the shutter, and threw handfuls of snow against the glass like gravel. She was washing the two tin plates at the kitchen sink when something cracked, high up, with a flat sharp sound like a pistol shot, and all the electric lights went out.

The silence afterwards was enormous.

"Line's down," Matteo's voice said calmly, from the darkness. "It does that. There's a lamp on the shelf by the door. I'll find it."

She heard him move. She heard the scrape of a match, and then a small yellow flower bloomed in the dark, and he came slowly through the arch with a hurricane lamp in his good hand and the light moving gold across his face. He set it on the table. The fire was banked to a deep red in the great hearth, and between its glow and the lamp the room had shrunk to a circle perhaps ten feet across, warm and amber and utterly cut off from the rest of the world.

"Well," said Sienna. "That's very convenient."

"I did not arrange it."

"I know you didn't." She dried her hands on her skirt. "You couldn't arrange a thing like this. You haven't the imagination."

He laughed. It came out of him like a breath, startled and warm, and after that it was simpler. They dragged the blankets from the bed in the white room, and the quilt, and a heap of old rugs from the porch, and made a nest before the fire at either end of the long sofa. The cold crept in as the night went on. By nine they had moved closer to the hearth without remarking on it, and by ten the sofa seemed to have shrunk, so that his shoulder lay about a hand's breadth from hers in the lamplight.

She asked him about his father.

She had not planned to. It came out of the quiet, the way things do in the dark, a question without a lock on it. She was sitting with her feet tucked under her and a blanket around her shoulders, looking into the red heart of the fire, and she said, "Rule two. What was he like?"

Matteo did not answer at once. He sat with his elbows on his knees and his bandaged hand in his lap, and the firelight ran along the edge of his jaw.

"Aurelio Bellandi," he said at last. "He was a very tall man and a very quiet one. He ran the port for thirty years and I do not think he raised his voice in any of them. He did not need to. When he walked into a room, the men would stop talking and look at their hands." A pause. "He taught me to do that. Not stop talking. Look at hands. He said a man's mouth will say anything, but his hands tell you what he's afraid of."

"Did he ever hold you?"

The question seemed to go into him very slowly. "No," said Matteo. "Not once. The only time he touched me was to correct my grip on a pen." His mouth moved. "I was six. He took my wrist and turned it, quite gently, and said, like this. It was the longest conversation we had that year."

"And your mother?"

"Livia." He said the name as though he had not said it aloud for a very long time. "She sang. Badly, I'm told. She died when I was twelve, in a winter very like this one, and my father had every portrait of her moved to the east corridor and never walked down it again." He turned his head. "That's the passage with the old harbor maps. You walk down it every night. I thought you should know why I never do."

She did not say she was sorry. It would have been the wrong thing. She sat quite still, with the blanket around her, and let it be said and be heard, and after a moment she heard herself begin.

"My mother was called Marit."

He did not move.

"She was the daughter of a herring skipper. Her father had a boat called the Gannet, and he used to say that a person should put salt in everything bitter, because the sea does it and the sea has been around longer than we have." She smiled into the fire. "She taught me with the coffee when I was seven. I've never told anyone why I do it. She died in the winter I was eleven. A fever that went to her chest. My father sat in the kitchen for a week with his coat on and could not be made to take it off. I think that was the year I learned to read letters from the bank."

"At eleven."

"Twelve, by the time I understood them." She drew up her knees. "I learned to watch faces, after that. His, mostly. I could tell from the way he put down his keys whether it had been a good day. I think I was the best technician in the hospital by the time I was twenty because I had been practicing since I was a child." Her voice had gone odd. "I never told that to anyone either."

The fire settled in the grate with a soft collapsing sound. Outside, the wind leaned on the walls of the lodge, and snow ticked at the glass, and neither of them said anything for a long time.

It was the first silence she had ever shared with him that did not ask for anything. She could feel it in the room like warmth. She thought, with great drowsy clarity: I have been afraid of this man for eleven weeks. And I am sitting beside him on a sofa in the dark, with half a pear in my stomach and my shoes off, and the only thing I am afraid of is that the fire will go out.

"You should sleep," Matteo said quietly.

"So should you."

"I'll wake you at six."

"You won't."

"No," he agreed, and she heard the smile in it.

She meant to answer. It seemed important. But the warmth had gone into her bones, and the lamp had grown very soft, and the long lovely weight of the day had begun to settle on her like a hand. Her head tipped sideways. She felt it go, and meant to catch it, and did not. It came to rest against something solid and warm, the shoulder of a gray wool jacket, with a faint smell of cedar and starch and wood smoke.

He went absolutely rigid.

She felt it through her whole cheek, the stiffening of every muscle, the held breath. It would have been funny, if she had had the energy. She tried to lift her head. She did not quite manage it.

"Matteo," she mumbled. "Rule three."

"Yes." His voice was almost inaudible. "Sienna. Would you like me to move?"

"No."

"Is this enough?"

"Not yet."

There was a pause so long that she thought she had imagined it. Then she felt him breathe out, very slowly, and the rigid line of his shoulder eased by a degree, and something light and careful settled over her arms. It was the quilt. He had drawn it up under her chin with one hand, the good one, the way one tucks in a child, and said, so softly that it was barely a sound, "May I?"

"Mm."

"I'll take that as yes."

She slept.

It was the deepest sleep she had had since the lab. There were no dreams in it, and no cold coin on the tongue, and no ruined carpet. There was only a long warm dark, and now and then, a long way off, a slow steady beat, which she knew somewhere in the back of her mind was a heart.

She woke to gray light.

It lay in a pale square across the flagstones, and the room smelled of cold ash and snow. The fire had burned down to a few red coals. The lamp had gone out, and the wind had dropped. Everything was so still that she could hear a single drip somewhere in the roof, patient as a clock. She lay with her cheek on something warm and rough, in a nest of quilt and rug, and for a long moment she did not remember where she was.

Then she did, and every nerve in her body woke at once.

She was asleep on his shoulder. She had been asleep on it, she calculated, for something very like eight hours. The quilt was tucked up round her chin, and a second blanket had been laid over her feet. Her hand had somehow come to rest against the front of his jacket, with her fingers curled loosely into the wool. He had not moved. She knew it by the angle of his arm, which lay along the back of the sofa behind her at a position that must have become unendurable around midnight, and by the quality of the stillness in his body, the careful held stillness of a man who has been awake for a very long time and has not allowed himself to shift.

She sat up very fast.

"What time is it?"

"Ten to seven." His voice was hoarse. He had not turned his head. He sat looking at the cold hearth with his jaw set and his eyes shadowed gray. "The snow stopped at four."

"You said you'd wake me at six."

"I did."

"It's ten to seven."

"You were asleep," said Matteo.

"That isn't an answer."

"It was the only one I wanted to give." He flexed the fingers of his good hand slowly, one by one, and she saw the faint wince cross his face as the blood came back. "Six hours. I counted. You didn't wake once. I've never seen anyone so entirely gone. I would not have disturbed it for the world."

"Your arm," said Sienna.

"It will return."

"Six hours." She pushed the hair out of her eyes. She was furious, and she did not know with whom. She had slept. She had slept like a stone on a man she had spent two months testing, on a shoulder that was supposed to be one of the most dangerous in the city, and woken in a nest of blankets that he had tucked around her with one hand. She had been safe. She had not been this safe, she thought, in any life she could remember. And the thing she felt about it was not gratitude. It was something much more like grief.

"You should have moved," she said, in a small cross voice.

"I did not wish to."

"Matteo."

"I know." He turned his head at last. His eyes were tired and very dark and entirely open. "I know, Sienna. I'll try to be more sensible next time."

He did not look as though he meant it. He looked, in the gray light, like a man who had been given a gift he did not intend to give back, and had decided that he would pay for it however he must.

She was still trying to find a reply when the sound of an engine came up the track.

Both of them went still. He was on his feet before she could breathe, and had her behind him, a wide black shape against the pale window, with his good hand going to his coat. Then he stopped. He let his shoulders drop, very slightly. A dark car had come out of the dripping pines and drawn up beside the porch, with snow thick on its roof and the wipers going.

"Marco," he said.

Marco got out slowly. He did not hurry across the porch, as he would have on any other morning. He stood for a moment with the snow falling off his hat, a big grave figure in a dark coat, and when he came in at the door she saw his face, and her stomach turned over.

He took off his hat. He held it in both hands.

"I'm sorry, sir. Miss." His voice was very level. "I didn't want to send word by the telephone in the village. I thought you should hear it from me."

"Marl," said Matteo.

"At five this morning. In his room over the chandler's." A pause. "The landlady found him. The gas heater. A fault in the flue, the police say. They have put it down to an accident."

The room did not change. The pale square of light lay across the floor. A drip fell somewhere in the roof, and then another, and then a long, long silence.

"Was it?" said Sienna.

Marco looked at her. His gray eyes were very steady and very tired.

"No, miss," he said. "I don't believe it was."