The silver sedan picked them up at the roundabout by the gravel works, and Dilly let it.

She had known it was there since Pellow Road. A good tail is a patient animal; it stays two cars back and one lane over, and it changes its hat at lights. This one had changed it twice. It was now a plain grey car with a cracked tail-light and a roof rack for nothing, and the driver was wearing a baseball cap, which was a mistake, because nobody on Kiln Road at ten on a Saturday morning had any reason to wear a cap against the sun when the sky was this low and white.

"Behind us," said Sel, mildly, from the back seat. He was reading the dashboard clock and not the mirror. "The grey one."

"You saw it?"

"I saw you stop looking at the left mirror and start looking at the right. It was very subtle. I congratulate you."

"Ilan," said Dilly. "At the next left, the one before the works, go into the yard and do a full circle round the weighbridge and come out again. Don't speed."

"Ma'am, that's a private."

"It's a Saturday. Nobody's at the weighbridge."

Ilan, who was young and sour and earning an hourly rate, drove into the gravel yard like a man being asked to jump off a roof, and did the circle. Dust rose in the white light. A yellow loader sat idle on a hill of crushed stone, and the grey car, a hundred yards back, slowed on the road and did a thing she would remember: it did not follow. It did not speed up, or fake a turn, or hang about for show. It simply stopped, in the open, and waited, as though it had been told that wherever they were going, it was going to be there too.

"They know where we're headed," she said.

"Do they?"

"Nobody tails a car they don't have to follow." She watched the sedan in the wing mirror, a small dark shape under a flat sky. "Unless the point is to be seen. I'd like a word with whoever's been teaching them."

"My uncle," said Sel, "has always been fond of being seen."

"This isn't your uncle. Your uncle doesn't wear a cap." She turned in her seat. "Ilan, back out slow. Left. Let's go see a gate."

* * *

Kiln Road ran out of town the way a thread runs out of a hem, getting thinner and then stopping. Beyond the gravel works there were three plots of rough grass, a shuttered tyre shop, a boarded-up diner with a sign still advertising hot pie, and then, on the left, set back behind a chain-link fence with a green plastic weave in it, a long low building the colour of wet cement.

There was a gate. It was twelve feet wide and set on rollers, and on the right-hand post, on a rectangle of enamel the size of a playing card, in white numerals on blue, was the number 41.

Nobody spoke. Ilan stopped the car and put it in park, and for a moment they all sat looking, the way people look at a house they have been told is theirs.

"It is very ugly," said Sel.

"It's meant to be."

"I think my grandmother liked ugly things. She said they were honest about what they were for." He took off his seat belt with fingers that were not quite steady. "Dilly, may I say something absurd?"

"You can say anything you like. I'm armed with a pen."

"I am more frightened of this building than I have ever been of the vault."

She turned and looked at him then. He was in the grey cardigan again, the old man's cardigan, with a navy collar showing under it, and he had put on his glasses to read the dash and not taken them off. He looked about nineteen. She had a sudden vivid sense that this was the face his father had worn, and his father before him, if you took away the money and the name and left only a person waiting for a result.

"We're not going in," she said. "Not today. We're going to look at the gate and get a feel for the guard and see who answers when we ring. Nobody signs anything. Nobody takes a pill from a stranger. We're two people who happen to have a key."

"And if the key fits?"

"Then we know the key fits." She put her hand on the door. "That's all."

The gate had a padlock, a thick brass one, new. It hung from a hasp on the left post beside a speaker grille and a button. Dilly got out. The wind that came across the grass was cold and smelt of cut stone. She looked, once, in every direction, and then at the lock. It was not made for the little brass key. The keyhole was a different shape.

She pressed the button.

Nothing happened for a minute. Then a click, and a voice, an old man's, thin, wary, Midland. "We're closed."

"My name is Dilnoza Karimova," said Dilly. "I'm Anselm Thornquist-Adeleke's wife."

Silence. Then the grille crackled, and the voice said, in quite a different tone: "Say that again."

"His wife. We were married yesterday at the Marren County Courthouse. He's in the car."

"Wait there."

They waited. A crow landed on the fence, considered them, and left. After four minutes by Dilly's watch a side door in the building opened and a man came out across the gravel at a pace between a walk and a trot. He was seventy at least, bent, with a grey moustache like a nailbrush, and he wore a blue work coat that had been washed so often it had gone the colour of sky. He carried a clipboard. When he reached the gate he stopped, and stood with his chest heaving and one hand pressed to his ribs, and looked through the chain-link at Sel, who had got out of the car and was standing on the verge with his hands behind him.

"You've got her eyes," the old man said.

"I am told so."

"I'm Teague. I've kept this gate thirty-one years. Thirty-one." He wiped his mouth with the back of his hand. "She said you'd come after the wedding. She said, not before. She said, not with a lawyer and not with a lot of noise. She was very clear." His gaze came back to Dilly, and he looked her up and down in a long, plain, assessing manner that reminded her of her mother in a market. "So this is the one."

"This is the one," said Sel.

"Right." Teague stepped back from the gate. "I can't let you in."

"We didn't ask to be let in."

"You did, though. It's what the button's for." He sounded wretched. "I'm sorry, miss. Sir. It's the terms. The Keeper comes in with his consort, the first Sunday of the month, and not on any other day, and not by himself, and not before a Close has been signed by the pair of them as man and wife. She wrote it down for me. I've got it on the clipboard."

"Tomorrow's the first Sunday," said Sel quietly.

"Is it? So it is." Teague lowered the clipboard. His hand shook very slightly. "Then I'll see you tomorrow at ten. Come in the blue door, not the front. Bring that key. It isn't for the gate."

"What is it for?"

"A door." The old man looked at the building, and then at the ground, and his moustache twitched. "I've never seen it opened. I'm told it hasn't been in eleven years. Since your father."

Sel's face did something small and terrible, and then did nothing at all.

"I should like," he said, "to know one thing before tomorrow. May I?"

"If it's mine to give."

"My grandmother came here once a month. Was she ever accompanied?"

"By the driver." Teague's thumb moved on the clipboard. "And by the one who signs the book."

"The book?"

"The visitor book. Everybody signs. Even her. She said a place that doesn't keep a record is a place you can't trust." He lifted the clipboard and turned it toward them, and Dilly saw a ruled page, a column of dates, and beside each date a name, in different hands, in different inks.

She read down the right-hand column. Most of the names were Odessa's, a long steel-nib signature with a hook. Beside hers, in the line below, appeared a second name every month. A round, confident, schoolgirl hand, the kind that dotted its i's with circles.

G. Thornquist.

"She was always with her aunt," said Teague. "Every first Sunday. Two years and a bit. Miss Greta drove herself, in the green car. And last Sunday, with the old lady two days dead," he shook his head, "she came again. By herself. Signed the book. Asked me what the Keeper's wife would be called, if there was one."

The wind dropped. In the quiet Dilly could hear the engine ticking in the car, and, far behind them on the road, a dark small shape in a plain grey sedan that had not moved.

"Greta," Sel said. His voice had gone the way it went at eleven fifty-eight. "Greta knows about Kiln Road."

"Knows? Miss, she's been inside it more than you have."

Dilly put her hand on his arm, and felt him shaking, and did not remove it.

"Mr. Teague," she said. "Last Sunday. What did she ask you for, exactly? Word for word."

The old man frowned, and his lips moved, and he looked at the sky. "She said, 'Teague, my aunt left a door. I know it's here. When the boy comes with his key, you'll ring me first.'" He swallowed. "I said I would. I wasn't to say I wouldn't. She's the Foundation. She signs my pension."

"Teague," Sel said gently. "Did you ring her?"

The old man's face crumpled by degrees, as paper does in water. He said nothing. He did not need to. Behind them, on the road, a car door slammed, and a man in a baseball cap walked slowly up the verge toward the gate, one hand lifted in an easy wave.