From the Couple of the Old Street entry form, resubmitted in two handwritings: "Please tell us in a few lines how your story began. Childhood neighbours. Lost touch. Found again. Still finding."

The first real date was Chengyan's idea, and he planned it the way he planned a roof.

He did it in pencil, on the back of a cutting list, at the bench, over three evenings, with Zhaoyu watching from the lathe in a state of silent and rapturous suffering. There were columns. There was a heading, in square capitals, that said WHERE and another that said WHEN and a third, which he rubbed out and rewrote four times, that said WHAT IF SHE DOES NOT LIKE IT. Under the last he had left a space, and could not for the life of him think what to put there.

"You could ask her," said Zhaoyu, helpfully, into his sleeve.

"I could not."

"It's what people do. They say, would you like to, and then the other person says yes or no, and then, "

"Zhaoyu."

"I'm only saying, you've kissed her in front of three thousand people and you've built her a mould and you carried her across a yard in a typhoon. I think you can say would you like a bowl of noodles."

"It's not a bowl of noodles," said Chengyan, with great dignity. "It's a particular bowl of noodles."

It was. It was at a small shop on the south bank, at the end of the alley behind the grain store, that he had been going to alone on Thursdays for nine years. It had four tables, a curtain of beads over the door, and a woman called Auntie Lu who made her own chilli oil in a barrel and had once told him that he ate like a man who had been left a great deal of money and wished to be careful with it. He had never taken anyone there. It had seemed to him a private sort of place, the kind that would not survive being explained.

He asked her on Wednesday, at the back gate, with a loaf under his arm and his heart going like a mallet.

"Would you like to come for noodles?"

"Now?"

"Tomorrow. At seven." He cleared his throat. "It's a date. A real one. I've, there's a list."

She stared at him. Then her whole face lit, slowly, from the mouth outward, like a window in a house at dusk. "A list," said Wenxi.

"It's very short."

"Can I see it?"

"No."

"Is there a column for what if I don't like it?"

He said nothing. His ears had begun, very faintly, to colour.

"Oh, Chengyan," said Wenxi, and she put the flat of her hand against his chest, over the pocket where a folded paper lay, and he thought for one wild moment that she was going to say something else. There was a small shadow in her eyes. It came and went, like a bird across a window. Then she laughed, and said, "Seven. I'll wear the orange dress," and was gone in a swing of skirt across the yard.

He stood for some time looking at the place where she had been.

* * *

Auntie Lu had put the table by the window.

She had done it without being asked, and without comment. She had wiped it down and set a small blue vase on it with three chrysanthemums, and she stood in the doorway of the kitchen with her arms folded and her chin up, a short broad woman of sixty with a face like a clenched fist, watching the young man come in out of the dusk with a girl in an orange dress at his elbow.

"Two," said Chengyan.

"I can count," said Auntie Lu.

She brought the noodles herself. They came in deep white bowls, steaming, a tangle of thin pale strands in a clear amber broth with a spoon of the red oil floating on top like a small sunset, and a little heap of pickled greens, and a soft-boiled egg split in the middle. The smell went straight up into his head. He sat with his hands on his knees and watched Wenxi take her chopsticks, and lift a mouthful, and blow on it, and put it in her mouth.

Her eyes closed.

He had been afraid of that moment for three days. He had gone through it in the dark: she would taste it, and she would be polite. She had eaten in hotel ballrooms. She had eaten at tables with seven forks. And here she was in a four-table shop with a bead curtain and a barrel of oil, and he had thought, she will smile at me, kindly, the way you smile at a man who has brought you a very small present.

She opened her eyes.

"Oh," said Wenxi, in a low voice. "Oh, that's good. That's, Chengyan, what is that?"

"Chilli oil."

"It's not chilli oil. It's, there's something, there's a sort of, " She took another mouthful, and chewed, and a small unguarded sound escaped her, the sound of a person who has bitten into something and found it a great deal better than the rumour. "There's a smoke in it. And a sweetness underneath. It's like a, I'd say it was orange peel, but that's silly."

"It's orange peel."

"It's what?"

"Dried. She puts it in the barrel. She says it takes the bitterness off the pepper." He found that he was smiling. He found, with some alarm, that he could not stop. "She won't tell anyone. She told me because I came every week for a year and never asked."

Wenxi put down her chopsticks. She put them down very carefully, parallel, as she did when something mattered, and she looked at him across the little table, and at the three chrysanthemums, and the window with the dark canal in it.

"You've been coming here alone," she said.

"Thursdays."

"For nine years."

"It's close to the grain store."

"It isn't close to anything," said Wenxi gently. "It's in an alley behind an alley."

He did not answer. He looked at his bowl. He thought, I should say something dry. It is what I do. I should say, it's a very good alley.

"I'm glad you brought me," said Wenxi.

"I'm glad you came."

"Is this on the list?"

"It was the first item."

"Then I'd like to tick it." She picked up her chopsticks again, and bent over the bowl, and he saw that her ears had gone pink. "Is there a second?"

* * *

There was a night market.

It was on the third evening of each week, in the long stone yard behind the old customs house, and it was the sort of place that exists only in towns where nothing has been done too well. The stalls ran in two crooked rows under strings of bare bulbs, each one swinging a little on its wire, and the smoke of a dozen small charcoal grills drifted up through them in blue ribbons. There were men selling roasted sweet potatoes out of oil drums. There were women with trays of fried dough twists and bowls of snail broth and small clay animals that whistled. A boy with a dented trumpet played the same eight bars of a pop song at a distance of forty feet from a girl with a violin who was playing, with equal conviction, something entirely different.

Wenxi, who had never in her life been so happy to be jostled, went through it like a swimmer.

She wanted everything. She stopped at a stall of carved soap and held a rose to her nose. She stood in front of a man who wrote names in sugar, with a ladle, on a marble slab, and he did her name in six strokes, a swift gold running line that hardened in the cool air into a thin glassy thing like a leaf, and she held it up to the bulbs and gave a small gasp. She bought a pair of paper fans, one pink and one green, and held them against her cheeks, one on each side, and said, "What do you think?" and he said, "You look like a very surprised peony," and she laughed so hard that a passing grandmother turned round to look.

"What is that?" she said, at the end of the second row.

It was a long pole wrapped in straw, and stuck all over with red.

They were candied hawthorn berries, a dozen to a stick, glazed in a hard clear shell of sugar so bright that the string of bulbs overhead shone in each one like a drop of fire. The old woman at the stall held one out. Wenxi took it. She held it up in front of her with the gravity of a woman receiving a sceptre, and looked at him over the top of it.

"Did you ever have these?"

"Once. I was nine."

"What happened?"

"I got a stone in my tooth," said Chengyan, "and I wouldn't tell anyone. I carried it round for a week."

"You didn't tell your grandfather?"

"I didn't want to be a trouble."

She looked at him for a moment. Then she bit into the first berry with a crack like a small branch breaking. She chewed. Her face went through three expressions in rapid succession, and ended in an enormous, slow, helpless pleasure, and she took the stick from her mouth and held it out to him, with a bite gone from the end.

"Here," she said. "There's no stone."

"How do you know?"

"I checked."

He took it. He ate a berry. It was tart and sweet and cold, the sugar breaking on his tongue in sharp bright splinters, and the smell of smoke and sweet potato and warm night air rose round him in a cloud. They stood in the yard in the swinging light, and passed the stick back and forth between them, a berry at a time, until there were only two left. She gave him the last but one. She ate the other. Her mouth was bright with sugar. He thought that if he were to live to be a hundred he would not forget the way she looked, in that moment, with the bulbs reflected in her eyes.

Her phone buzzed.

It was in the pocket of the orange dress. He felt it, against his hip, through the thin cloth, a small shiver. Her smile did not move. But he saw her hand go to the pocket, quite lightly, and close on the shape, and press it flat, and hold it there, like a person laying a palm over a drum.

"Somebody wants you," said Chengyan.

"It's nothing."

"It might be Grandma."

"It's not Grandma. She texts in capitals." She laughed, and slid her hand through his arm, and drew him on toward the whistling clay animals. "Come on. I want to see the one that looks like a duck."

He went with her. He did not ask. He noticed, as one notices the first small crack in a plank, that it had been a very practised sort of laugh.

* * *

On Saturday morning she asked him to teach her to row.

It was a thing she said at the breakfast table, quite casually, over a bowl of congee, and Grandma Su, who was stirring a pot at the stove, did not so much as turn her head. But the wooden spoon stopped for a moment. Wenxi saw it. She saw the small stillness in the old woman's back, and then the spoon resumed its slow circles, and she looked down at her bowl and ate faster.

He took her to Fang Dehai's slipway at seven, in a white mist, with the sun a pale coin behind the reeds.

The cedar skiff lay at the foot of the steps like a long sleeping fish. He steadied it with one boot against the stone and held out his hand. She stepped down into it, in her old linen trousers and his blue shirt, with her hair in a plait, and sat in the front seat with her paddle across her knees. Then she turned round.

"Not like that," she said. "I want to do it myself. You sit behind. You say nothing. You only tell me when I'm wrong."

"That will be often."

"I'm counting on it."

He got in behind her. The boat sighed under his weight. He sat with his own paddle laid across the gunwales, unused, and looked at her back.

She was a very bad rower. He had not thought that she could be worse than she was in August, but she had achieved it. She dug in on the left and skimmed on the right. She splashed. She leaned too far forward and the prow nodded into a clump of reeds, and a moorhen rose with a furious clatter and fled. She made a noise of rage, and flung her hair back, and tried again.

"Breathe," said Chengyan.

"I am breathing."

"You're holding it."

"I'm not."

"You've stopped. I can hear it. It's like listening to a person who has swallowed a bell."

"It's concentration."

"It's fear," he said, quite gently. "There's nobody here. Let it out."

She drew a long breath. It shook. She let it out in a rush, with her head bent, and he heard her laugh, a small helpless sound, and then the paddle dipped, and drew, and the skiff slid forward through the mist for the length of a single stroke, straight as a ruled line.

"There," he said. "That's one."

"One what?"

"One good stroke."

She did another. It was not as good. She did a third, and that one ran true. The mist lay on the water in long pale scarves, and the willows stood up out of it with their branches hanging down in the stillness, and the only sounds were the drip of her blade and the slow wet slap of the hull. He watched the muscles move under the blue cotton of her shoulders. He thought of a girl of eight who had stood on the end of his workbench and told him that one day she was going to make a cake the size of a house.

He did not tell her what to do. He sat and breathed, a little louder than he needed to, in and out, and after a while she began to fall into it. She breathed when he did. She dipped when he drew in. It was as if a thread had been run between them through the grey air, and the boat was no more than a little weight that hung from it.

"You're doing it," said Chengyan.

She did not turn round. She said, "I know," in a small awed voice, and the mist parted before them, and the sun came through.

* * *

They went to the willow on Sunday afternoon.

It was Wenxi's idea. She had a plan, which she did not explain, and she had brought with her a thing in a cloth, which she would not show him, and she led him up the worn steps of Liu Bridge with a bright flushed face and her hand in his, and down the far side, and through the green curtain of the branches, where she stopped.

"Right," she said. "Back to the trunk."

"Wenxi, "

"Humour me."

The tree stood in the gold afternoon, broad and rough, with the canal sliding past beneath it and the light coming down through the leaves in long moving bars. He stood against it. He felt the bark through his shirt, deeply furrowed, faintly warm. At the height of his shoulder, a long way above where he had stood at sixteen, a row of small pale marks ran up the wood like the rungs of a ladder, and the oldest of them were healing over.

She unwrapped the cloth.

It was the horn-handled knife. His grandmother's. She had taken it from the shelf in the workshop without asking, and she held it now in both hands, in the soft light, like a thing that might still be alive.

"I want to do it properly," said Wenxi. "We haven't measured since I was seventeen. Eight years. We've got to catch up." She turned him by the shoulders. "Stand flat."

"I am standing flat."

"You're always standing flat. You're the one who doesn't need to. It's me." She took off her shoes. She set them side by side in the grass, and put her back against the trunk beside him, a hand's breadth to his right, and stood very straight with her heels against the roots. "Now. Somebody mark it."

"Who?"

"Nobody's here. You'll have to do it for both."

He took the knife. It was a small warm weight in his hand. He held it level against the crown of her head, as he had held it a dozen times when they were children, with one knuckle lightly on her hair, and she stood quite still with her chin lifted and her eyes shut, and the leaves moved over them both.

"Well?" said Wenxi.

He was looking at the bark. There were the old notches, hers on the right, the last of them at seventeen, grey and soft and nearly gone. He found it. It was the faintest of lines. He held his knife a little above it.

"It's half a finger," he said slowly. "Above the last one."

"Half a finger!" Her eyes flew open. "I've grown?"

"I don't know. You've been eight years in a city. People do, at nineteen."

"Chengyan!"

"I'm only reading what's there."

"I'm taller. I'm taller than I was. After all that shouting, I was right, it's going to say so, it's going to say it in writing, " She had begun to laugh, a wild delighted laugh, with her hands pressed to her mouth.

"You're on your toes," said Chengyan.

"I am not."

"Heels up. I can see the grass."

"I'm standing flat. You can ask the willow."

"The willow is not an independent witness."

"It's the only one we've got," said Wenxi, and it came out light, and then it did not, because her face had changed. She stood with her back against the bark and her hands spread flat on it, and she was looking at him, and the laughter had gone out of her eyes as water goes out of a basin, leaving something clear and very still. "Last time," she said. "I stood here, and you said, still on her toes. And I said, flat. And I wrote, witness, the willow. And then I went away."

"Yes."

"I want it in the record," said Wenxi. "This time. In the tree. I'm standing flat."

He looked at her.

She stood in the bars of light, barefoot, with her plait coming down and her chin up and her heels pressed hard into the roots, and he thought that he had never seen a creature so plainly resolved to be believed. He did not argue. He set the point of the knife to the bark, half a finger above the old grey notch, and cut.

It took a long time. The bark was tough and the blade was old, and the little curl that came away was damp and green and smelled of rain. He cut it deep, so that it would last. He cut a small straight line, and then, below it, because it was her mark and she was entitled to it, he cut the date. It was only the year, in tiny square figures. Then he stepped back.

"There," he said. "It's recorded. Flat."

"Thank you."

"It is in dispute."

"It's in the tree," said Wenxi. "That's what counts."

She held out her hand. He gave her the knife.

She did not mark herself again. She turned, and stood on tiptoe, and stretched up the whole length of her arm, and pressed the point to the bark on the left-hand side, where his marks were, at the height of the crown of his head. She had to reach. It was a good deal more than a finger above the last. It was, he saw, almost exactly where the first of the five extra notches on the back of a boxwood mould would have fallen, if a man had been measuring from memory.

She cut. She did it carefully, with her tongue between her teeth, and the point slid and caught and went on. When she had done she cut the year, in small crooked figures, a little uphill.

"You've cut mine," said Chengyan.

"Somebody had to. It's the same."

"I haven't grown."

"I don't know," said Wenxi softly, and set the flat of her hand against the new mark, and then against his chest, over the pocket with a folded paper in it. "I think perhaps you have."

They stood under the willow with the knife between them and the canal talking quietly to itself at their feet. A leaf came down. It landed on the grass beside her shoes. Her eyes were very bright. She looked as though she would say something else, something that lay behind her teeth with its hand on the latch, and he waited, as he had always waited, with the patience of a man who has learned that the best joints are the ones you do not hurry.

She did not say it.

She laughed, instead, a quick breathless laugh, and kissed him, hard, on the mouth, in the green shade, with her hands in his collar, and when she drew back there was a smear of sap on her cheek and her eyes were wet.

"Witness," said Wenxi, "the willow."

He held her. He put his chin on the top of her head, and the long drooping branches swayed round them like a curtain, and under his hand, on the left side of the trunk, the two new notches shone pale and wet in the afternoon, one a little above the other, side by side.

He did not ask what she had been about to say. It was a thing he was learning. You could wait for a person, he thought, until the wood told you it was ready. But it did not tell him whether it was ready, or merely holding its breath. And somewhere in the pocket of an orange dress, a hundred yards off, on the bank where she had left her bag, a small phone lay face down in the grass and buzzed, once, and was still.