It rained on the sixth of August, for the first time in five weeks.

It came down at dusk without any warning, out of a sky that had been the color of an old coin since the first of July, and it fell so hard and so straight that for a quarter of an hour the whole of Tern Street stood in a silver roar and nobody could hear anything else. Edmund ran out in his shirtsleeves to drag the barrow in. The gutters sang. The old men went off their pavement chairs like startled pigeons, and from the harbor below came a long deep sigh, as of a great animal letting go its breath. Sienna stood at the shop door with her hands held out over the step and the water running down her wrists, and she laughed aloud, for no reason, and then stopped, abruptly, because it was the first time in eleven days that she had.

The heat went out of the town. By eleven the air was cool and smelled of wet stone and tar and the green breath of the cypresses far up the hill. She sat at the oilcloth table in the little back kitchen with a cup of tea going cold at her elbow and the blue notebook open in front of her, and she was not thinking of anything at all, when someone knocked.

It was not the knock of a neighbor. It was two knuckles, precise and light, repeated once, with a pause between, like the tapping of a physician on a chest. Edmund looked up from his book. He had put on his glasses to read and had been holding the same page for twenty minutes. "At this hour?" he said.

Sienna was already on her feet.

She went through the dark shop with the little brass lamp in her hand, past the stacked coils of rope and the brass fittings behind glass, and she drew back the bolt. The bell tinkled. The rain blew in across the threshold in a cold fine slant, and on the step, under the dripping iron bracket of the sign, a tall woman stood in a gray raincoat with the collar turned up and her sleek dark hair plastered to her cheek.

She was carrying a leather bag in one hand and a small battered suitcase in the other. She had no umbrella. Behind her, at the edge of the pavement, a thin boy in a cap stood with his hands in his pockets, looking as if he would very much like to be somewhere else, and at the end of the street a long black car sat dark under the dripping lamp.

"Miss Hale," said Helena Roux.

It was the voice of the white room. It was cool and exact and level, and Sienna, who had sat beside it through a whole night with a green line running across a screen, heard the faint high hairline crack at the bottom of it. "I am sorry," said Helena. "I did not know where else to go. I had Pavel's cousin bring me up from the tram. I told him it was a medical matter. I am not, I think, sure any longer that it is not."

"Come in."

"I have no right..."

"Come in out of that," said Edmund Hale.

He had come up behind them in his carpet slippers, with his book still in his hand and a candle in a saucer in the other. He did not know who she was. He had never seen her in his life. He took one look at the wet gray coat and the white face and the suitcase, and a great gentle commanding fuss came over him like a change of weather. He took the bag out of her hand. He called her madam. He sat her down at the oilcloth before the stove, and drew a rug round her shoulders, and put a kettle on, and sent Pavel's cousin up the street with a coin for a hot pie, and he did it all without asking a single question and without once looking at Sienna.

Helena sat in the lamplight with her wet hands folded in her lap and looked at him as if she had been handed something she did not know how to hold.

"Thank you," she said at last.

"Not at all, madam. It's a poor sort of house, but it's got a bolt." He cleared his throat. "I'll be upstairs. You'll want to talk. I shan't listen. I'm very deaf, you know, in my left ear." He went out with the candle, and they heard his step on the stair, slow and creaking and very audible, going away to the very top of the house.

Sienna made the tea herself. She tested the pot. She tested the cup, and the milk, and the sugar, and she held the strip up to the lamp so that Helena could see it, and the tall woman looked at it, and the faint hard muscles at the corners of her mouth relaxed a very little.

"Thank God," said Helena. "I should have been distressed if you hadn't." She took the cup in both hands. Her fingers were white with cold, and the china chattered once against her teeth. "He has begun to taste mine first, you know. Every night this week. He comes to my door in the evening with a tray, and he lifts the cup and sips and says, delicious, and sets it down in front of me, with a smile." She drank. "I find that I do not like it at all."

"You left the house."

"I left it at nine o'clock. I walked out of the kitchen door in my coat with my bag. I said to Mrs. Venn that I was going to a patient in the old town. She looked at me and said nothing at all, which is the most eloquent thing that woman has ever done, and went on shelling beans." A cracked breath that was almost a laugh. "I could not stay. There is no room in that house that is not listened to. I knew it before your note, before the hatch. I knew it from the way my door was tried at night. It is a doctor's gift, you understand. One learns very early to know a listened-to person. I saw it in the glass."

Sienna sat down across from her. She put her hands flat on the oilcloth. She did not say anything. She had learned, over a long winter, from a man she did not intend to think about, that the best help one person can give another is to leave a silence open and wait.

Helena set down the cup.

"I told you in the clinic," she said, "that if I spoke a name I should be dead by the weekend. It has been three weeks since I said it, and I am still here, and I am so very tired of being afraid. I should like to say it all, in order, once, to someone who will not tell me that it does not matter. I think you are the only person I know who will not." Her gray eyes came up. "May I?"

"Please."

"Three years ago," said Helena, "on a wet Thursday in the spring, Dario Vance came to the clinic annex with a tin of biscuits and asked me to teach him to write like me."

She said it flatly. She sat very straight in the straight chair with her hands in her lap, and the lamplight lay along the sleek wet line of her hair, and her voice did not once shake. It was the voice, Sienna thought, of a woman reading out her own case notes, because it was the only way she could be sure of getting to the end.

"He said that it was a joke. He said he had a nephew who was being married, a godson, in Carrow, and he wished to send a prescription to the bridegroom as a surprise, a little paper from the family doctor, ordering rest and a great deal of champagne. It was an old man's whim. I thought it charming. I was lonely, God help me, and flattered, and he is very good company. I sat with him for an hour in my own room, over my own tea, and showed him how I turn an R." She lifted one hand and traced it on the oilcloth with a fingertip: a quick upright stroke with a tiny flick to the right at the end. "I showed him the hook. I showed him where I lift the pen. I told him that no one could ever copy it, because it is all in the speed. And he said, with that smile, that he had always been a very patient man."

Her finger stopped.

"He was a very good pupil," said Helena.

"And last March."

"Last March, the spring before your wedding. I found two prescriptions in the dispensary book, for a sedative that I had not written. In my hand." Her mouth twisted. "I told you that, in the clinic. I told you I tore them out. I did not tell you that I knew whose they were the moment I saw them. I stood in the dispensary with the book open and I thought, Dario, you absurd man, you have been practicing. And I closed the book. I told myself it was a joke that had gone too far. I told myself it was nothing at all, and for a year I went on telling myself, until the afternoon a girl in a green dress sat in my annex and said that she had been listening to a sterilizer log."

The kettle ticked on the stove. Rain ran in the gutter outside the window with a sound like a long thin conversation.

"Why were you afraid?" said Sienna.

She asked it as gently as she knew how. It was the question that had sat at the middle of Helena Roux since a white room in October, and she saw it go in. Helena closed her eyes.

"Because of Aurelio," she said.

She opened them again. They were wet, and steady.

"I became the family's physician eleven years ago. Aurelio Bellandi had a cancer of the lung by then, though he did not know it, and he did not wish to. He had been a very large and powerful man, and it took him two years to die. I tended him through all of it. I was thirty, and I admired him enormously. He taught me to play chess." A faint smile. "He did not like to lose, and I never let him win, and it was the only honest conversation he had in that house."

She drew a long breath.

"On the last night, nine years ago in November, he was in great pain. The morphine was no longer enough. I gave him what I judged was right, a larger dose than the day before, proper, entered in my own book. I left the syringe on the table. I was exhausted. I had been awake for thirty hours. Dario was sitting in the chair at the foot of the bed, as he had for a week, and he said, go and lie down, my dear, I shall watch him. And I went. I slept for four hours in the dressing room. When I woke, Aurelio was dead."

Sienna did not move.

"I signed the certificate. Heart failure, from the disease. It was credible. And in the morning Dario took my hand in both of his and said, you gave him a mercy, Helena. I have never forgotten it. I took it for kindness." Her voice had gone very low. "Three years ago, on the wet Thursday, after I had shown him how to turn an R, he took a paper out of his pocket case and laid it on the table beside the biscuits. It was a prescription. It was dated the night Aurelio died. It was in my hand, my very hand, and it ordered a dose of morphine that was nearly three times the one I had given."

The lamp hissed. A clock ticked somewhere over the stove.

"He said that he had found it in the old man's papers," said Helena. "He said that he had kept it all those years so that no one should misunderstand. He said he only wished me to know that I need never be frightened, because it would never leave his possession." She laughed, a thin cracked sound with no mirth in it. "I did not write it. I know that I did not. I have gone over that night a thousand times and I have the book. And yet I have never in nine years known whether the last syringe was mine. I was asleep. I do not know what was in it when I came back. I have only a gentle old man's word that it was kindness, and a paper in my own handwriting that says it was not."

"He made you his," said Sienna slowly.

"He made me the person who could be made a murderess by a stroke of a pen. And then he was very kind to me for three years." Her hands, folded in her lap, were not still. "He sent flowers on my birthday. He asked after my mother. He was the only person in that house who ever remembered that I had one."

It was the worst kind of cruelty, thought Sienna, and the gentlest. It was the cruelty that wears a cardigan and asks after your mother. She put out her hand across the oilcloth and covered the tall woman's, and Helena did not take hers away.

"The glass," said Sienna.

"Yes." Helena drew a long breath. "I have been waiting for you to ask me that."

She reached down beside her chair. From the leather bag she took a small dog-eared green book with a stiff cloth cover, an ordinary clinical day-book of the sort that every doctor in the city keeps in a drawer, and laid it on the table between them. She did not open it.

"You found a compound in the grooves of the crystal," she said. "A quiet one. A white salt of something that does nothing at all until it meets an acid. I read your report on the night of the lemons, and I sat on my bed with the page in my lap, and I could not breathe."

"You knew it."

"I knew the shape of it. I knew where I had seen it." She opened the book at a place marked with a strip of tape. "The spring before last. April, before the wedding. A consignment came to the annex, by van, from a shipping firm I had never dealt with. Vance Maritime Trust. It was a single sealed carton, five hundred grams of white powder in a brown glass jar, labeled in my own hand, stannous preparation for glass care." She laid her finger on a line. "Here. Entered in the dispensary book, and signed. H.R."

Sienna looked at the line.

It was a perfect line. The quick upright R, the little flick at the end. She did not need the magnifier. She knew, as she knew her own thumb, that the pen had left the paper between the H and the R.

"I did not order it," said Helena. "I did not write that label. I did not sign that entry. I found it in July, a few weeks after, when I went to look for a bottle of ether and counted eleven shelves of my own stock and found one I did not recognize." Her mouth was very thin. "And Dario was in the doorway of the annex, with his hat in his hand, and he said, that is for the old glass, my dear, the cedar room crystal clouds in the damp, I asked Fenwick's man to see to it. And he smiled. And I said, how thoughtful. And I put it back on the shelf."

"And it vanished."

"In September. The week the flutes came for sterilization." She shut the book. "I wish that I could say I had suspected. I did not. I sat in my room with my chess set and told myself that old men like to be useful."

There was a silence. The rain eased a little and then came on again, harder.

"The night at the clinic," said Sienna. "In February. In the kitchen when I took your hand, and you looked at Matteo." She was surprised at how steadily she said it. "You told me that he asked you to teach him. You looked at him, and then you stopped. I thought for six months that you meant him."

"I know that you did."

"Did you?"

"No." The word came fiercely. Helena lifted her head. "God, no. I looked at him because I was sorry for him." Her eyes were very bright. "Do you understand? I have watched that boy since he was twenty-two. I watched him come home from a night with his father, white to the lips, and sit in my clinic for an hour with his hands between his knees, not speaking, because it was the only room in the house where nobody wanted anything of him. I do not know that there is anything in the world so terrible as a child who has been told stories at bedtime by the person who is going to destroy him." She drew breath. "I was not afraid of him. I was afraid for him. Dario sat on the edge of his bed and told him tales about tug captains, and I stood in the passage and listened, and I thought, that is a very kind man. It is the only thing I ever thought."

She put the day-book into Sienna's hands.

"The real log," she said. "The one in the annex, chained to the wall, was always for show. I never trusted it. I kept this in a locked drawer in my own bedroom, in my own hand, with the dates and the hours. Every time Dario came to the clinic when I was out of it, and every time the key was moved. There are eleven entries. You will find the sixth of October, which I did not mention, because I was in Carrow, and the log says that the autoclave was run by H.R. at twenty to three in the morning, and this book says, in plain words, that the key to the annex was on Dario's chain." She took something from the pocket of her wet coat and laid it on the oilcloth beside it. It was a small brass key on a loop of black ribbon, worn smooth. "And this."

"What is it?"

"The door in the east wing. Beyond his study, the little room he keeps locked. He has never in thirty years shown it to anyone." A faint, dry, awful smile. "I had it copied in March, by a locksmith in the old town, in a moment of what I can only call madness. I have not been able to use it. I was too much of a coward. But I thought that you would not be."

Sienna turned the key over in her fingers. It was cold and very light. She thought of a candle burned low at three in the morning in a room at the end of a long passage, and a pen with a barrel worn smooth, and a man in his shirtsleeves who was not pleased with the third F.

"The girl who does the fires," said Helena, quietly. "The one you sent your note about."

Sienna looked up.

"Her name is Nessa Brill. She is eighteen. She has a sister in Carrow of twelve, with a hole in her heart." She was looking at the lamp. "I wrote the referral myself, two winters ago, because the child was blue to the lips and nobody in that town would take her. It was a surgeon in the capital. It cost a very great sum." A pause. "Dario paid it. He walked into my annex one morning and said, you must send the little girl to Mr. Ansley, I have spoken to him, I should be very glad to be allowed. It was the kindest thing that I ever saw him do. I believed it for a year."

"And then."

"And then I understood what it had bought." Her voice cracked. "They found her yesterday morning at the scullery pump with her apron over her face. Mrs. Venn told me. She said she had never seen a person cry like it, and that when she put her arms round her, the girl said only, I did not know what it was for. I thought it was only to listen." Helena closed her eyes. "It is the cruelest thing he does, you know. He does not threaten. He gives you something you cannot refuse, and waits."

Sienna said nothing for a long time.

She sat with the key in one hand and the little green book in the other, in the warm low circle of her father's lamp. She was thinking, with a cold clear part of her mind that went on working, as it had gone on working in a basement on the worst nights of her life. She was thinking of the sums. She laid out what she had like instruments on a tray. A button of buffalo horn. A clause fourteen in a typed annex. A cut page. A cheque, a note, a card. Fourteen invoices. Now a log, and a key, and a doctor in a wet coat who had been made a murderess by a signature and had sat at an oilcloth table and told it plain.

"You should go to the police," said Helena. "Inspector Hollis is a decent man. He has no love for Rusk."

"With what?"

"With all of it."

"With a button from a dozen coats and a letter in a dead man's hand that he will say Matteo wrote, and a doctor who admits that she cannot swear to a dose." Sienna said it without heat. "I can prove a method, Helena. I can prove it in a laboratory in forty minutes. I can't prove an intention. He is the senior trustee of a harbor and the nearest friend of the Chief Magistrate's cousin. He sent me an invitation by the post this week and wrote on it in ink that was still wet. If I walk into Inspector Hollis's office with a green book and a brass key, he will thank me, and take notes, and go to Cypress Hill with a bouquet."

"Then what?"

"He has chosen the day." She laid the key down on the oilcloth. "The fourteenth. A hundred and forty people in a single room. Every man he owes and every man who owes him. He wants us all in the hall at six o'clock with the old banners down. If I cancel it, he will choose another night, and I shan't know which." She heard her own voice, very small and very hard. "I would rather know when. I would rather walk in with my eyes open."

"You would be walking into it."

"I'd be walking into it," said Sienna, "with a chemistry set."

Helena stared at her. And then, slowly, against every effort of her will, the corners of her mouth began to shake. It was not a laugh. It was something very close to it, and a great deal more tired. She put her hand over her face, and her shoulders heaved once, and she took it away again with her eyes streaming.

"God," she said. "You are so very much like him."

The words dropped into the room.

Sienna did not answer. She looked at the green book on the table, and the brass key, and the long wet gray coat dripping on the floor, and she felt something shift in her chest, very slowly, like a boat coming off a shingle bank on the turn of the tide. She did not ask. She did not say that she did not wish to hear. She waited, with her hands flat on the oilcloth, and in a little while Helena wiped her face with a corner of the rug and spoke again, much more quietly.

"I will tell you the last thing, and then I shall try to sleep. It is the thing I was most afraid to say."

"Go on."

"He said something to me once. It was in June, on the day after the lemonade. I was changing the dressing on Matteo's arm, in the green room, and Dario came in with a tray. He stood at the foot of the bed, looking down at the boy asleep, and then he looked at me." She drew breath. "He said, gently, that I need not be afraid. He said that whatever happened in this house, he would never let any harm come to you."

Sienna's hands went cold on the oilcloth.

"He meant it," said Helena. "That is the thing I cannot get past. I watched his face. It was sincere. He said, she is the daughter I would have chosen, Helena. If I had had one. I do not think I have ever loved anyone as I have come to love that child." Her voice failed, and she steadied it. "And he will do it, my dear. He will do exactly what he has planned. He will do it weeping."

Outside the rain had slackened to a whisper. A drop fell from the iron bracket of the sign and struck the step with a small clear sound. Somewhere at the top of the old house a board creaked, and a man's slow voice said, to nobody, that he was a little hard of hearing in his left ear. Sienna sat still at the table with the key under her hand, and the whole narrow kitchen seemed to hold its breath around her, as it had once, in a different house, on a different night, around a pair of glasses and a white satin ribbon.

The daughter I would have chosen.

She had thought, for a month, that the worst thing a man could do to her was keep her. She saw now that she had been wrong. The worst was to be loved, sincerely, by the person who meant to bury you.