From the Couple of the Old Street entry form: "Please tell us in a few lines how your story began."

They rehearsed on the bridge, because the bridge was public, and Clause Four had a long reach.

It was a warm, close night, the kind that comes at the end of June when the air has been cooked all day and has not yet remembered how to cool. The canal lay black and glassy under the arch. A few windows glowed along the water, and somewhere downstream a radio was playing a thin, sweet song about a boat. Wenxi sat on the low parapet with a stack of index cards in her lap and a flask of barley tea at her elbow, and Chengyan sat beside her, a respectable foot away, with his folding rule turning over and over in one hand.

"Question one," she said, reading from the top card. "How did your romance begin?"

"It crept."

"That's my answer. You can't have my answer."

"It's the true one."

"It's the one I wrote down at four this morning, and it is mine." She struck a line through it, then wrote it again underneath his name, with a small flourish. "All right. You say, we grew up next door and then we didn't see each other, and when I came back it was like finding a room in your own house you'd forgotten about. That's what I'd say, if I were you."

"I would not say that."

"What would you say?"

He considered it with the gravity of a man asked to define a load-bearing wall. "She came back," said Chengyan. "And the roof stopped leaking."

She looked at him. She had meant to laugh. Something in her throat got in the way, and she looked down at the cards instead, and said in a brisk voice, "That's very good. Keep that."

They went on until midnight. They agreed on the rules, which were the same rules as before, with a few small additions. Everything must be true, or as true as could be managed. Nothing was to be invented that the other might have to remember. If one of them stumbled, the other would take the question, and no one was to look at the judges' table for longer than two seconds, because Zhaoyu had read somewhere that a liar's eyes go to the person they are lying to.

"Zhaoyu has read a great deal," said Wenxi.

"He has a spreadsheet for it."

"Of course he does."

A frog started up under the bridge, then another. The tea was cold. She screwed the cap onto the flask and found that she did not want to go home. She wanted to stay exactly here, on the warm stone, with the paper cards going soft in her fingers and a man beside her turning a rule over in his hand, rehearsing a love story that was not true in a voice that kept forgetting to be careful.

"Last one," she said. "Question seven. Who said it first?"

He stopped turning the rule.

"Said what?"

"Whatever it is that people say. I love you, I suppose. Or, I don't know, I'd like to see more of you." Her face was hot. She kept her eyes on the card. "They'll want to know who went first."

"We say nobody has."

"It's been twelve weeks."

"Then we say we haven't needed to."

She looked up.

He was not looking at her. He was looking at the water, and his profile in the dim was calm and stern and very still, like a face cut into a coin. But the rule in his hand had gone quiet, and she saw his thumb press the brass hinge so hard that the knuckle showed white.

"That's a good answer," said Wenxi, and her voice came out smaller than she meant.

"Yes," said Chengyan. "I thought so."

They walked home the long way, a foot apart, and neither of them said anything about it at all.

The interviews were held on the second floor of the committee hall, in a long, high, whitewashed room with a polished table at one end and a row of tall windows that looked out over the canal. Someone had set out five cardboard name cards and five glasses of water. Someone else had put a vase of white lilies in the corner, which gave the whole room the faint unreal solemnity of a funeral parlour.

Wenxi sat in a hard wooden chair with her hands folded in her lap. She had on her cream dress with the plum blossoms at the collar, because it was the one that made her look like a person who could be believed. Chengyan sat beside her in the blue shirt from the wedding. He had ironed it himself. The left cuff had a crease down it as sharp as a joint, and she had spent the first three minutes of the waiting trying not to look at it.

"Nervous?" he said, under his breath.

"No."

"You are twisting your hair."

"I'm styling it."

"It's coming off in your hand."

She looked down. She had wound the end of her ponytail so tightly round her finger that the tip had gone white. She unwound it. He rubbed the back of his neck.

"You are rubbing your neck," she said.

"It's stiff."

"It's been stiff for three weeks."

"It's a very old neck," said Chengyan, and the door at the end of the room opened, and the judges came in.

There were five of them, as before. The stout lady from the tourism board, whose name card said MADAM GAO, settled herself in the middle with a sigh of satisfaction and opened a leather folder. The thin gentleman in the bow tie, MR. BEI, took the seat to her left and straightened his cuffs. The restaurateur from the provincial capital, MS. RONG, took out a silver pen. The elderly retired teacher, MR. HAO, with his folded handkerchief already protruding from his breast pocket, lowered himself into his chair as though it were a bath.

Shen Haoran came last, and sat at the end. He had on a pale grey suit and no tie, and his notebook lay closed in front of him with a pencil laid across it. He looked tired in the clean light from the windows. He looked, she thought, like a man who had been up late reading something that had upset him, and had put on a smile over it as one puts on a coat.

"Ms. Su. Mr. Gu," said Madam Gao. "Thank you for coming. We will be brief. We ask each couple the same questions, and we ask you to answer as honestly as you can. There are no wrong answers." She smiled. "Except, of course, the ones that are false."

There was a silence in which Wenxi heard her own pulse.

"We'll do our best," said Chengyan.

The first questions were gentle. How long had they known each other? Where did they live? What did they do for a living? Wenxi answered them in the old bright voice, with the dimple, and felt it settle on her like a well-fitting coat. Chengyan answered in monosyllables. Ms. Rong asked about the willow-pattern mould, which had been entered as their joint product, and he said, "It's a tool," and she said, "It's a very beautiful tool," and he rubbed his neck and said nothing.

Then Mr. Hao leaned forward with his handkerchief in his hand.

"I should like to ask," he said, in a voice like an old clock being wound, "about the beginning. How did it start? I am an old man and I am sentimental, and I like to know how things begin."

"It crept," said Wenxi.

She heard the answer leave her mouth in the smooth confident tone she had practised, and she felt Chengyan beside her go quiet and approving.

"Crept," said Mr. Hao, delighted.

"We grew up next door. And then I went away, and when I came back it was like finding a room in my own house I had forgotten about." She had not meant to say the last part. It had simply followed the first, like a second step. "And I didn't know whether to go in."

"And you did."

"I'm still deciding," said Wenxi, and heard how true it was, and kept smiling.

Mr. Hao dabbed his eye. "Splendid. And who, if I may ask, took the first step? I mean the very first. Who said, let us walk out together?"

She had the answer. It was on the fourth card. We say neither of us. We say it was something we did without noticing.

But she opened her mouth, and what came out was, "He carried me through a flood."

The judges looked at her.

"When I was twelve," said Wenxi. Her voice had run away from her, and she found that she could not catch it. "The canal rose, in September. There was a cake. I wouldn't leave it. He picked me up and put me over his shoulder and walked me through the water to the bridge, and I held the cake the whole way. And I remember thinking, with the water up to his knees, and my hair in my mouth, that nobody had ever taken me anywhere before. That nobody had ever gone to so much trouble to put me down somewhere safe." She drew breath. "So that was the first date. I think. If I'm honest. It was the first time anybody took me anywhere."

There was a long silence in the room.

"A flood," said Ms. Rong, writing.

"A flood," said Mr. Bei, and glanced at Madam Gao, who put a hand to her collar.

"I have heard a version of this story," said Shen Haoran.

It was the first time he had spoken. His voice was soft and level, and he did not raise his eyes from the closed notebook. "At the tea house, two weeks ago. Mr. Gu told it to a party of visitors. There was a cake in it, and roses made of sugar, and he mentioned a great deal about stubbornness. He did not say a word about a first date."

Wenxi's blood went still. She could feel the whole table looking at her.

"The cake," she said, "was a chaperone."

Mr. Hao made a noise like a kettle. Madam Gao put her folder over her face. And beside her, Wenxi felt Chengyan draw a long, slow, careful breath, and knew that he was going to speak, and knew that she had no idea what he would say.

"She wore a green dress," said Chengyan.

She turned her head.

He was looking straight at the judges. His hands lay flat on his knees. His voice was the voice in which he read out the dimensions of a window, perfectly steady and quite low, and he did not seem to know that his ears had begun to colour.

"It had white buttons down the front," he said. "Seven of them. The hem was torn, on the left side, about this long." He held up his thumb and finger, three inches apart. "She caught it on the nail of the gate when the water came in. She'd been so proud of that dress. Her grandmother had made it for the birthday. And she never said anything about the tear. She stood on the stairs with the cake and cried about the roses, and I knew it was the dress she was really crying about, but she'd decided it was too small a thing to say."

Wenxi could not breathe.

"So I carried her with the torn side against me," said Chengyan. "So the water wouldn't get it. It didn't matter. She was soaked to the neck. But I thought, at least, it will not get worse."

The room had gone absolutely silent. A fly bumped against the window. On the canal below, a boatman called to another, and the sound floated up thin and clear and a long way off.

She had not known.

She had been twelve years old. She had torn the hem on the gate, in the dark, and it had been the worst thing that had happened to her that year, worse than the flood and the ruined sugar roses, because her grandmother had sat up three nights at the machine to make that dress. She had hidden the tear under her arm. She had told no one. She had carried it for fourteen years like a stone in her shoe, and it had never occurred to her, not once, that a boy with a girl over his shoulder and the canal at his knees might have seen it, and turned his body to the wind.

She forgot the two-second rule. She forgot the dimple. She turned and looked at him with her whole face, and she knew, quite distantly, that it was open as a window, and that she could not shut it.

Chengyan did not look at her. But the muscle at the corner of his jaw moved once, and she knew that he knew.

Mr. Hao blew his nose with a sound like a trumpet.

"Thank you," said Madam Gao, in a rather unsteady voice, and wrote something down, and underlined it twice.

It was Shen Haoran who asked the last question.

He had been quiet through the rest, through Ms. Rong's enquiries about the festival and Mr. Bei's about the finances of the bakery. He sat at the end of the table with his hands folded on the closed notebook, listening with an expression that Wenxi could not read, and when the others had finished, and Madam Gao began to say the usual words about thanks and results, he lifted one finger.

"If I may."

"Of course, Mr. Shen."

He looked at them. It was a long, quiet look, level and tired and not unkind, and for a moment she thought he was going to ask about the mould, or the money, or the neat arithmetic that had brought them to this table in the first place. She braced herself.

"What is it," said Shen, "that makes two people stay?"

It was such a simple question that for a moment she did not understand it.

"When it is difficult," he said. "When there is no prize and no audience. When one of them could leave, and the other would let them. What keeps people together?" He turned his pencil over on the notebook. "I have been in this work a long time. I have asked it of a great many couples. I have never once received an answer I believed."

The room waited. Outside, a heron lifted from the canal with a slow thud of wings.

Wenxi opened her mouth.

"I know the sound of the step," said Wenxi.

"I know the sound of the step," said Chengyan.

They had spoken at the same instant. The words were the same, to the syllable, in the same low unplanned tone. They hung in the white room, one over the other, like two notes struck at once.

She turned her head. He turned his. They stared at one another, a foot apart, with identical expressions of blank astonishment.

"The, " said Wenxi.

"The footsteps," said Chengyan.

"You know mine?"

"Left foot. There's a catch." His ears were scarlet now. "Since you jumped off the bridge."

"I know yours," said Wenxi. "You walk like you're apologising to the ground."

"I do not."

"You put your heel down first and then you sort of, you hesitate." She was laughing, she found, a breathless, helpless, cracked little laugh, and she could not stop it. "I heard you across the whole courtyard at the banquet. I'd have known you with my eyes shut. I'd know it at the bottom of a canal."

"That's rather morbid."

"You started it!"

"I said something perfectly reasonable."

"You said the same thing I did!"

"I said it second."

"It was at exactly the same time!"

She had her hand over her mouth. He had put his over his eyes. Their shoulders were shaking. At the end of the table, Mr. Hao was weeping into his handkerchief with unconcealed joy, and Madam Gao had given up her folder and was simply looking at them, flushed and shining, as at a play she had not expected to enjoy. And Shen Haoran, at the far end, with his pencil lying quite still across his notebook, was not smiling.

He sat very straight. His face was calm. But something in it had gone out and come back, like a light behind a curtain, and for the length of a breath he looked past them both, at the white wall, at nothing, with the faraway face of a man hearing a step on a stair that had been silent for years.

"Thank you," he said at last, quite gently. "That will do."

They went out into the corridor on legs that did not feel their own.

The committee hall had a long wooden stair, wide and shallow and smelling of floor wax, with a window at the turn that let in a bar of afternoon sun. They got as far as the window. Wenxi put her hand on the sill, and found that it was shaking so hard that her ring tapped against the glass.

"I'm fine," she said. "I'm perfectly fine."

"You are not."

"It's a reaction. It's only adrenaline. I've had this before, at weddings. After the cake goes out." Her teeth had begun to chatter. "Chengyan, I told them you carried me, as a, as a date. I've no idea why I said it. It was on the cards, I'd written it, I had a perfectly good answer, and then it just came out, and I thought, he'll be furious, we agreed, nothing invented, and I didn't invent it, I swear, it's all true, it's just that I never said it before, not to anyone, not even to, "

"Wenxi."

"Yes?"

"Stop."

She stopped. She stood there with her hand on the sill and her mouth open, and he came up beside her and looked at the window. The sun lay across his face, and his eyes in it were very dark and very calm.

"The dress," she said. "How did you know about the dress?"

"I saw it."

"I hid it."

"You hid it badly," said Chengyan. "You held your arm like this the whole way to the bridge." He pressed his elbow to his side to show her. "I thought, she has torn something. And I knew you'd never say."

She made a small sound. It was not a word. She put the back of her wrist against her mouth.

He looked at her hand on the sill, white-knuckled, shaking, and she saw him look. She saw the quick unguarded flicker of something in his face, and the way his own hand came up an inch from his side, and hung there.

"Is it under the clause?" said Wenxi, in a whisper. "Right now?"

He glanced up the stair. He glanced down it. The corridor behind them was empty. The judges were in the room, murmuring, a long way off, and the window was cut in the thick old wall, and no one in the world could see them but the heron on the canal.

"There's no one here," said Chengyan.

He took her hand.

He did it simply, without ceremony, as a man takes hold of a rope. His fingers closed round hers, warm and large and rough, and the shaking in her arm stopped. It did not fade. It stopped, all at once, as if a switch had been thrown, and she stood in the bar of afternoon light with her hand held fast in his and the whole of her body slowly going still.

They did not speak. He did not look at his watch. A faint sound of a fiddle drifted up from the street, and a boy ran by below, shouting, and the sun moved a quarter of an inch across the floor.

"I think we did well," said Wenxi, after a time.

"I think we did something."

"What do you think it was?"

He did not answer. His thumb moved once along the side of her hand, back and forth, in the slow absent way of a man testing the grain of a board. She closed her eyes. She thought of the green dress with the seven white buttons, and a boy in the dark with a torn hem against his chest. She thought, I am going to have to tell him everything, and was astonished to discover that she was no longer afraid of the thought. She was only afraid of the time it would take.