Highland Tower stood on the northern hill above the river, thirty-eight stories of glass and brushed steel, and from the street it looked like nothing so much as a blade that had been driven into the ground and left standing.

Elias arrived at six minutes to seven on Saturday evening, in the old gray Volvo, with a canvas suitcase on the passenger seat and his hands locked on the wheel. He had driven the long way. He had crossed the river by the upper bridge, and circled the hill twice, and parked in the visitors' garage with the engine running for eleven minutes before he could make himself turn it off. Now he sat looking at the dashboard clock, watching the green numerals change.

6:54.

He could still turn around. He told himself that quite clearly. It was a fact, as solid as the steering wheel under his hands. He could start the engine, and drive back across the bridge, and sleep in his narrow bed above the laundromat, and tell the captain on Monday morning that he had thought better of it. No one would be harmed. It was only a room.

6:55.

He got out of the car.

The lobby was a vast cool hall of pale stone and glass, lit from below by long strips of white light, and so quiet that his footsteps rang. A young man in a gray suit sat behind a curved desk at the far end, and looked up as Elias approached with the practiced, discreet blankness of someone who has been paid to notice everything and remark on nothing.

"Dr. Mercer?"

"Yes."

"Captain Harrow is expecting you." The young man inclined his head. "Thirty-one. The elevator on the left. Your keycard will be waiting at the door." A small, polite smile. "He asked me to tell you that you may take as long as you like."

Elias thanked him. He did not know what else to do. He crossed the stone floor with his suitcase in one hand, and stepped into the elevator, and the doors slid shut behind him with a long soft sigh like a breath let go.

It rose in silence. Numbers glowed and faded above the door. Ten, twenty, thirty. He stood in the center of the polished steel cage with his reflection staring back at him from every wall, a small pale figure in a dark coat and black gloves, and counted the floors. His pulse was steady. His hands were steady. He had told himself that he would be steady, and he was, and he wished with all his heart that he could have been anything else.

The doors opened on thirty-one.

The hallway was carpeted in deep gray. There were four doors in all, spaced far apart, each one painted a flat unadorned white. At the end of the corridor, directly opposite the elevator, one of them was standing open.

Luke stood in it.

He had not come out. He stood exactly on the line of the doorframe, with one hand resting on the edge of the open door and the other at his side, in a plain dark sweater and gray trousers. His feet were bare. It was the first thing Elias saw, and it struck him with a small ridiculous force. He had never imagined the man without shoes. His hair was damp, as if he had recently showered, and in the warm gold light behind him the lines of his face looked softer than Elias had ever seen them, and much more tired.

"Doctor," he said.

"Captain."

"You came."

"I said I would."

"Yes." Luke's voice was very low. "I did not wish to presume."

They stood looking at each other down the length of the empty hall. Elias felt the weight of the suitcase in his hand and thought, absurdly, that he was a child arriving at a boarding school. Then he walked forward, one step and another, along the gray carpet, and each footfall was soundless, and the light from the open door grew and widened until it touched his shoes.

He crossed the threshold.

He heard the door close behind him. It shut with a very soft click, a sound that was almost nothing, and yet it went through him like the closing of a cell. He did not turn. He stood in the entrance of Luke Harrow's apartment with the suitcase hanging from his hand, and the warm air closed around him, and for a long moment neither of them said anything at all.

It was very clean.

That was the first impression, and for a while the only one. The room in which he stood was large and bare and high, with white walls and a floor of dark polished wood, and it contained almost nothing. A long gray sofa. A low table of black glass. A single tall lamp, switched on, throwing a circle of amber light across the boards. There was a bookcase along one wall, with perhaps forty books in it, aligned by height. There was a kitchen at the far end, steel and white, as spotless as an operating theater.

There were no photographs. He looked for them without meaning to. He looked along the walls and the shelves and the top of the bookcase, and found none. No framed faces, no smiling groups on beaches, no pictures of a mother in a church hat. Nothing on the walls at all. It was the room of a man who had been alone in it for a very long time, and who had never quite managed to believe that he lived there.

It looked, he thought, a great deal like his own.

The thought was so unwelcome that he turned his head away. He found himself looking at the far wall, where there was a window.

It was a very large window. It ran from floor to ceiling, a single enormous pane of glass, and beyond it lay the whole sweep of the river valley, a long dark ribbon of water lit here and there by the glow of bridges and the slow drift of boats. The city spread out below like a map made of light. He could see the cranes of the harbor, and the pale rectangle of the stadium, and a long slow line of headlamps crawling over the upper bridge.

There were three windows in the room. He saw that a moment later. Two of them gave onto the river, east and south, uncovered, black and glittering.

The third was on the north wall, the one that faced the hill.

It was covered.

A heavy curtain of dark gray linen had been drawn across it from edge to edge, so thickly that not a thread of light came through. It hung in perfectly straight folds, from rod to floor, a plain wall of cloth. The other windows stood naked to the night. This one had been shut away. And Elias, who had stood on a harbor wall eight days ago and looked across the water at a black ridge against the dawn, knew at once what lay behind the curtain.

From this height, on a clear night, with no cloud between, a man standing at that window could see the top of the hill.

He could see a chimney, standing alone against the stars.

Elias did not move. He stood quite still, with the suitcase in his hand, and looked at the curtain, and a very strange thing happened in his chest. It was not anger. It was not fear. It was something slow and cold and heavy, like water rising in a well.

He thought: he draws it every night.

He thought: he cannot bear to look.

And then, in the same moment, with a sort of horror: neither can I.

"I thought you might like the river," said Luke, quietly, behind him.

He had come in without a sound. Elias had not heard him. He stood a little distance away, on the other side of the lamp, with his hands loosely at his sides, and his eyes followed Elias's gaze to the gray curtain, and stayed there a moment, and returned.

"It is a fine view," said Elias. His voice was perfectly level.

"It is the only one worth having."

"Yes."

They did not speak of the curtain.

It was the most extraordinary thing, afterward, how entirely they did not speak of it. They stood in the warm lamplit room with the whole dark city glittering at one side and a drawn gray wall of cloth at the other, and each of them knew perfectly well what the other had seen, and neither said a word. The silence between them was so full that Elias could feel it against his skin.

"I will show you the room," said Luke.

It was at the end of a short passage, behind a plain white door. Luke opened it, and stood back, and did not go in.

Elias stood on the threshold.

It was a small room, square and clean, with pale walls and a window that looked toward the river. A bed stood against the right-hand wall, a real bed, wide and low, with a dark blue cover turned neatly down at one corner. A chair. A lamp. A narrow chest of drawers. A rug in some soft gray wool, and on the rug, set squarely at the foot of the bed, a pair of slippers, new, still joined by a paper tag.

He saw, in a single sweep, all of it. And a slow cold feeling began to move over him, from the nape of his neck down his spine.

The bed was heaped with blankets. There were four, folded in layers, one upon another, in wool and flannel and a heavy down. A second pillow lay beside the first. Beside the lamp stood a small steel thermos, dented, with a cup for a lid, and beside that a covered plate, and next to the plate a white china teapot on a tray. There was a heating pad on the chair, coiled neatly, its cord plugged into the wall. And on the wall by the door, in a small white plastic casing, a thermostat.

He crossed to it. He read the number.

Seventy-two degrees.

He turned around slowly.

"I took the liberty," said Luke, from the doorway, "of adjusting the temperature. I did not know what you preferred."

"It is seventy-two."

"Yes."

"That is my preference."

"Is it?" Luke's tone was mild, and his face did not change. "A fortunate guess."

It was not a guess. He knew that. He stood in the warm still room with the thermostat at his back and the whole calm, careful arrangement spread before him, the four blankets, the thermos, the pad, the slippers still joined by their paper tag, and he saw it with the cold clear sight of a man looking at a wound. Not a single thing in this room had been chosen at random. Every object had been picked by someone who knew, precisely and without error, what the occupant would need. The warmth. The tea, not coffee. The heating pad for hands that never quite stopped aching. The very pitch of the temperature, set to the exact degree at which Elias kept his own studio, in his own cold room, in the long gray hours before dawn.

He had never told anyone. He had never in his life said the number aloud.

"How did you know?" he said.

It was barely a whisper. The room was so quiet that it carried.

For a moment Luke did not answer. He stood in the doorway with his hand against the frame, and in the warm light of the lamp the lines of his face were unreadable. Then, quite gently, he said, "You carry a small thermometer in your coat pocket, Doctor. I have seen you check it at the crime scenes. It is always at seventy-two, or very close."

It was true. It was perfectly true. Elias did carry such a thermometer, a small steel pencil of a thing, in the left pocket of his coat. He had never imagined anyone had noticed.

It was an explanation. It was an entirely reasonable one. And he stood in the little room and felt the hair rise along his arms, because it had been delivered so smoothly, and so fast.

"I see," he said.

"I hope it is not intrusive."

"It is not."

"If anything is wrong, I will change it."

"Nothing is wrong."

It was a lie. He had begun to find that they came to him very easily, now. It was just that this one cost a little more.

Luke inclined his head. "There is soup in the kitchen, when you are ready," he said. "I have made enough for two. You need not join me. I will leave a bowl on the counter, and you may take it into your room."

"I will eat with you."

He had not meant to say it. It came out dry and flat, a thing his mouth had decided without consulting the rest of him. Luke stopped with his hand half lifted.

"If it is convenient," Elias added.

"It is," said Luke, after a moment. His voice was oddly soft. "It is very convenient."

They ate in the kitchen, at a plain wooden table pushed against the wall. It was the one piece of furniture in the room that looked as though it had been used.

Luke sat at one end. Elias sat at the other. There were six feet of scrubbed oak between them, and the soup was between them too, in a wide white tureen, steaming. It was the same soup. He knew it at the first taste: chicken and rice and ginger, thin and golden and warm. He ate it slowly, with a small tarnished spoon, and did not look up.

For a long time neither of them spoke. The kitchen was warm and bright and smelled of ginger and bread. Outside the window the lights of the city glittered, and a long way below a train went by along the river, so small and silent that it seemed to be moving in a dream. The only sound was the soft clink of spoons against china.

It was, Elias realized, a very peaceful meal.

He did not know how that had happened. He could not account for it. He sat at a table with a murderer, and ate his soup, and the air between them held something very close to ease. Neither spoke. Neither needed to. They sat in the amber light with their heads bent, like two men who had shared a house for years and had long since run out of things to say.

It was dangerous. He knew that. He knew it as one knows the first faint pull of a current. And still he could not seem to make himself resist it.

"There is more," said Luke, at last.

"Thank you."

"The ladle is by your hand."

Elias looked. It was a large steel ladle, lying across the lid of the tureen, with its long handle toward him. He reached for it.

At the same moment, Luke leaned forward. He had been about to push the tureen across the table. He stretched out his arm, and his hand came down on the handle of the ladle, from the other side.

They stopped.

Their hands were very close. The black leather of Elias's glove and the bare brown skin of the other man's palm lay on the same length of steel, perhaps half an inch apart. Elias felt the heat of that skin through the air, a faint dry warmth like the radiance off a stove. He saw the white scar across the knuckle. He saw a small pulse beating in the wrist.

Neither moved.

The kitchen was absolutely silent. A drop of water fell from the tap into the sink. Somewhere, far below, a car horn sounded and died away.

Half an inch.

He could feel his heart in his throat. He could feel the whole length of his arm as if it had been turned to glass. He did not look up. He could not. He looked at the hand on the ladle, large and scarred and still, and he thought of the way it had closed around his own in a hospital room, warm through the leather. He thought of the way it had held a knife.

Luke drew his hand away.

He did it slowly, without haste. He took it back across the table and laid it on his knee, and the ladle lay between them on the lid, bright and abandoned.

"Forgive me," he said. His voice was very low.

"It is nothing."

"I was careless."

"It is nothing," said Elias again, and took up the ladle, and filled his bowl.

His hand did not shake. He was quite proud of that. He ladled out the soup, and set the ladle down, and lifted his spoon, and ate. But the warmth stayed on his glove for a long time afterward, a ghost of a pressure, like the memory of a touch that had never quite occurred.

When the bowls were empty, Luke rose and carried them to the sink. Elias stayed where he was, with his hands folded on the table, and watched the broad back bending over the water.

"Captain."

"Yes?"

"I will say the conditions again." He kept his voice quite steady. "I will have the door locked. I will hold the only key. No one enters that room without invitation."

"Yes."

"No questions about my habits."

"No."

"No questions about my gloves."

"None." Luke did not turn. He stood with the water running over his hands. "I gave you my word."

"Yes."

"I would like to add something, if I may."

"Please."

There was a short silence. The tap ran. Then the water stopped, and Luke dried his hands slowly on a towel, and turned. He stood with his back against the sink and the towel in his hands, and his eyes were dark and grave.

"I will never open that door," he said, "unless I am invited."

He said it quite plainly. He did not lower his voice, or lean on the words, or ask to be believed. He simply stated it, as a man states the time. But it went through the quiet kitchen like a struck bell, and Elias understood, with a sudden clarity that made his skin prickle, that it was not a promise about a room.

It was something larger, and more dangerous, and much harder to hold.

"I understand," he said.

"I hoped that you would."

Elias rose. He took his bowl to the sink, though it was empty, and rinsed it, and set it on the rack. He did it without looking at the man beside him. He was aware of the warmth of him, and the faint clean scent of soap, and the quiet sound of his breathing. He dried his hands. He folded the towel. Then he turned, with great care, and walked out of the kitchen, and down the short passage, to the door of the little room.

Luke followed, a pace behind, and stopped.

He did not come near. He stopped a good four feet from the threshold, in the dim passage, with his hands at his sides and the light of the lamp behind him throwing his shadow long across the floor. For a moment he seemed to hesitate. Then, very slowly, he lifted one hand and rested it against the doorframe, high up, above his own head, the way a man leans against a wall when he is very tired.

"Good night, Doctor," he said.

"Good night."

"If you need anything, I will be at the end of the hall. I do not sleep deeply. You need only say my name."

"I will not need anything."

"Of course." The faintest smile. "But I wished you to know."

Elias stepped into the room. He turned. They stood looking at each other across the width of the threshold, a doorway, a few feet of carpet, a line that neither crossed. He saw the tired dark eyes, and the hand against the frame, and the shadows beneath the cheekbones, and some small bright current ran between them that he did not dare to name.

"Luke," he said.

It was out before he knew. It was a single syllable, quiet, unguarded, and it fell into the passage like a stone into a pool.

Luke did not move. He did not breathe. His hand, against the doorframe, had gone absolutely still. Something passed across his face, so quickly and so completely that Elias could not tell what it was, and when it was gone the whole man seemed to have changed. He looked suddenly very young.

"Yes?" he said.

It was barely audible.

Elias found that he had nothing to say. The word had come from nowhere. He had not planned it. He had not wanted it. It had risen in him, as the name had risen on a tile floor in a dark laboratory, bright and terrible and entirely beyond his control. He stood there with his heart pounding and his face quite blank and the whole warm silence of the apartment pressing in around him.

"Good night," he said.

Luke closed his eyes.

It was a very brief motion, almost a flinch. Then he opened them, and smiled, and it was a real smile, small and crooked and unguarded, the first Elias had ever seen on that face.

"Good night, Elias," he said.

He took his hand from the doorframe. He stepped back, and turned, and walked away down the passage, and the sound of his bare feet on the wooden floor dwindled and faded into the quiet. A door opened and closed.

Elias shut his own.

He turned the lock. It was a plain brass bolt, new, well oiled. He drew it across, and stood with his forehead against the cool wood, and breathed.

Then he took the key from the inside of the lock, and put it in his pocket, where he could feel it against his thigh.

He did not sleep.

The room was warm. The bed was wide and soft and dressed in clean linen that smelled faintly of cedar, and four blankets lay across it in layers, and the heating pad glowed gently on the chair. He lay on top of the covers, in his clothes, with his gloves still on, and his eyes open, and looked at the ceiling. The window beside him showed a square of black sky. A single light moved across it, very high, the winking green of an airplane crossing the dark.

Tomorrow was the eighteenth.

He had known it all week. He had counted. It was the ninth day from the last. If the pattern held, if the clockwork that had run so cleanly through September and into October had not run down, then somewhere in this city, in a house or a car or a lit office, a man was making his plans for the morning. A man who had been marked. A man who did not know.

He lay and thought of it. He thought of the nine days, and the five bodies, and the dates written square and black on a whiteboard. He thought of the door at the end of the hall.

Somewhere past midnight, he heard a sound.

It was very faint. It came through the wall, from the far end of the apartment, a slow soft tread on bare wood. It moved down the passage. It paused. It came on again, and he lay quite motionless and listened to it, and counted the steps. Eleven. Twelve. Thirteen.

It stopped.

It stopped, he thought, quite near the other end of the hall. Outside the door of the room that held the secret. He could not see it. He did not need to. He knew, as clearly as if he had stood at the keyhole, that a man in bare feet was standing in the dark in front of a gray steel door, with his hand held an inch from the lock.

It was perfectly silent. He did not hear a key. He did not hear a breath.

The seconds went by. A minute. Two. He lay in the warm dark with his eyes wide open and heard nothing at all, and the silence grew thick, and heavy, and strange. It seemed to hum.

Five minutes.

Ten.

He could not tell how long it lasted. He lay quite still, and in his chest his heart beat out a slow and heavy rhythm, and he thought of the wind, and the gravel, and a voice on a telephone saying, a place I go once a year.

At last, very softly, a floorboard creaked.

The footsteps turned. They went back along the passage, slowly, as a man walks who is carrying something he has not been able to put down. They reached a door, and paused, and a latch clicked, and the apartment was quiet again.

Elias lay in the dark, with the key in his pocket and the gloves on his hands, and watched the green light cross the sky.

He had not heard a murder. He had not heard an escape. He had heard only a man in a hallway, standing for a very long time before a door that he did not open.

He did not know why that should be the thing that frightened him most.