From the Agreement of Temporary Cooperation, Clause 3: "Hand-holding shall be limited to three (3) occasions per day, in public only, not exceeding five minutes each. Interlaced fingers count as two."

The second round of the campaign began, as all things in Yunxi began, with Tang Rui and a clipboard.

"Walk of the Old Street," she announced, pinning a sheet of cream paper to the wall of the tea house with four brass tacks. "It is a task, not a round. Do not look at me like that. The festival is the round. This is a warm-up, and you will be scored on it, and you will enjoy it very much."

"What does it involve?" said Wenxi.

"Forty minutes. Twenty paying visitors from the county tour bus, who have been told that they are going to meet a real couple of the old street and hear how their love story began. You walk them from the east dock to the bridge. You point at things. You tell the story." Tang Rui tapped the paper. "The judges will be walking behind, at a discreet distance, with notebooks."

"Which story?" said Chengyan.

He was leaning in the doorway of the tea house with his arms folded, looking at the clipboard as if it might bite. He had come straight from the workshop. There was cedar dust on his sleeve and a pencil behind his ear, and he had the expression of a man who had agreed to many things in the last month and was beginning to keep a list.

"Your story," said Tang Rui sweetly. "The one you told on the application. Childhood neighbours, lost touch, found again."

"That is three facts," said Chengyan. "It is not a story."

"Then make it into one. You have until Saturday."

They wrote the script on the bridge.

It was a bright, cool afternoon, with a thin wind coming down the canal and the willow stirring overhead, and they sat on the low parapet at the crest of the arch with a pad of paper between them and a flask of tea at Wenxi's elbow. She had a pencil. He had his folding rule, which he had taken to carrying everywhere and now used, she noticed, as a kind of worry stone, turning it over and over in one hand.

"We start at the dock," she said. "I'll say, welcome to Yunxi, where I was born and where I'm still, I mean, where I've come back to. And then you say something about the water."

"What about the water?"

"I don't know. That it's old."

"It is old."

"Then say that."

"It is very old," said Chengyan, in the voice of a man reading a plaque.

She laughed. She had not meant to. It broke out of her and she caught it with her hand, and when she looked at him he was watching her with a faintly wary pleasure, as though he had thrown a stone and was surprised to hear it land in water.

"All right," she said. "We'll work on the delivery. Now, the second stop. The willow. I think the willow is the heart of the thing. We can say that we met under it."

"We didn't meet under it. We were born next door."

"We can say we grew up under it."

"That's true."

"I know. That is why I'm suggesting it." She wrote it down. "Everything we say should be true, if we can manage it. It's easier to remember. And if somebody asks a follow-up question, we won't have to invent anything."

He was quiet for a moment. He turned the rule over in his fingers.

"Your rule," he said. "True things."

"It's not a clause."

"It could be."

"It would be a very short clause. Tell the truth, except about the one thing." She said it lightly, and then heard what she had said, and her pencil stopped. The wind lifted the corner of the paper. She put her hand on it.

He did not ask which thing. He did not say anything at all, and she was grateful, and a little sorry, in equal parts.

"The third stop," she said briskly, "is the tea house. Tang Rui will give everyone a cup. And the last stop, the grand finale, is the bridge, where we hold hands for the photograph."

"Which count?"

"Which count. The first is at the start. The second is at the middle. The third is at the finish. That's fifteen minutes in total, spread over forty. We are well within the clause."

"Mm," said Chengyan, and wrote the arrangement on the back of his hand with the carpenter's pencil, in tiny square capitals, as if it were a measurement.

She watched him do it. She noticed, with the same small helpless tenderness that kept ambushing her these days, that he had written the numbers in the order of a cutting list.

The visitors arrived on Saturday at half past ten, off a bus the colour of a boiled sweet.

They were exactly what she had expected: twenty people in sun hats and walking shoes, with cameras around their necks and an air of cheerful, slightly sunburnt goodwill. There was a family with three children, a pair of retired schoolteachers, a group of young women in matching scarves, and a very large gentleman who introduced himself as a retired customs officer and asked at once whether the canal was safe to drink.

"Welcome to Yunxi," said Wenxi, with the full dimple.

She had practised it in the mirror. She had said it forty times to the rabbit on her ceiling. It came out clear and warm and entirely natural, and the visitors beamed at her, and she felt the old shop-window brightness settle over her like a coat she knew how to wear.

"I'm Su Wenxi. This is Gu Chengyan. We're going to show you our town."

"And you're together," said one of the young women in scarves, with a little shiver of delight. "The real couple. We saw you in the picture."

"The one on the boat," said another.

"With the arm," said a third.

Chengyan, beside her, did something to the back of his neck with one hand. It was the gesture he used when a board had gone wrong, a quick hard rub with the heel of his palm as if to push the problem back inside. "Yes," he said. "The arm."

They set off.

She had not thought about the judges. She had thought about the script, and the stops, and the clause, but not about the small silent group that fell in behind the last of the visitors at a distance of twenty paces. There were three of them, today: the stout lady from the tourism board, the retired teacher with his handkerchief, and Shen Haoran, in his grey jacket, with his notebook closed under his arm and a pleasant face. They walked with their hands behind their backs, like men visiting a museum, and they did not speak.

Wenxi felt them on her neck all the way down the dock.

The first stop went well. She talked about the water, and Chengyan said that it was very old, and the retired customs officer wrote it down. At the second stop, under the willow, she told the story of the notches in the bark, and the children crowded to touch them, and the youngest, a girl of five with a gap in her teeth, put her thumb in one and said in a loud whisper, "Somebody was here."

"Two somebodies," said Wenxi.

"Which are you?"

"I'm the lower one."

"Why are you lower?"

"Because," said Wenxi, "he is a liar and I was standing flat."

The visitors laughed. Chengyan said, "She was on her toes," and the whole party roared, and for a moment it was almost a performance, bright and easy, a thing they were doing together. She stole a glance at him. He was looking at the willow, with a faint softening about the mouth.

It was time for the first hand.

They had agreed on the signal. She would reach for the strap of her bag, and he would reach for her hand. It was an arrangement of impeccable discipline. She reached for the strap. She felt his fingers close around hers, warm and rough and exactly where she had known they would be, and the checking watch on his other wrist gave a small, almost inaudible tick.

"One," he said, under his breath.

"One," said Wenxi.

They walked on, across the bridge and down the far steps, and along the canal path in the slanting light. She had forgotten how easy it was to talk with a person's hand in hers. Her sentences came out smoother. The bright voice had begun to loosen at the edges, and a different one, slower and more her own, was coming up underneath it.

"And that," said Wenxi, pointing, "is Sixth Alley. That's my grandmother's bakery, Su Ji. It's seventy years old. And next door, the one with the big doors, is Gu Family Workshop. It's older."

"Eighty-one," said Chengyan.

"Eighty-one. He always wins."

"Do you live next door to each other?" asked the retired schoolteacher.

"Wall to wall."

"How romantic," said the schoolteacher's wife.

"It is very loud," said Chengyan. "She sings."

"I do not sing!"

"You hum. When you cook. I have heard it through the plaster for three weeks."

"It's an opera tune."

"It is the same bar of an opera tune," said Chengyan gravely. "Over and over. I have started to dream it."

The young women in scarves shrieked with delight. Wenxi, to her own astonishment, was laughing so hard that she nearly let go of his hand, and she remembered to tighten her grip just in time, and felt his fingers answer.

The watch ticked. Five minutes. He released her at the exact second, as always, cleanly, and the empty place on her palm went cool.

It was at the tea house, over a paper cup of green tea, that the script began to come apart.

It was the retired customs officer who did it. He sat down on a bench in the courtyard with a great grunt, took a sip, and said, in the voice of a man accustomed to examining documents, "And what, may I ask, was the moment? When you knew?"

Wenxi opened her mouth. The prepared answer was ready, a smooth little paragraph about reunion and old friendship and the way the town had drawn them back together. She had a sentence that began, it was something we both felt, and she had been rather proud of it.

Chengyan said, "The flood."

She turned her head.

"When we were twelve," said Chengyan. He was not looking at her. He was looking at the cup in his hands. "The canal came up in September. It was a bad year. The water was in the alley to the knee and the whole street was out with buckets. I was fifteen. She was twelve." He stopped, and rubbed the back of his neck. "She had a cake that she'd made. She'd been making it for three days. It was for her grandmother's birthday, and it was a big one, three tiers, with sugar roses, and she had been so proud of it. And when the water came up, she wouldn't leave without it."

The courtyard had gone very quiet.

"She was standing on the stairs of the shop, with this cake in both arms, and the water coming in through the door, and everybody shouting at her to put it down. And she wouldn't. She stood there with her chin up, like a small general. She said, it's Grandma's birthday." He paused. "So I carried her."

"You carried the cake," said Wenxi, very faintly.

"I carried you," said Chengyan. "You carried the cake. We got to the bridge and it was only a little bit squashed. She wouldn't let me eat any. And I remember thinking, that I'd never in my life seen anyone so, " He stopped again. "So stubborn about something that wasn't hers."

Nobody spoke. A fly buzzed in the jasmine. The retired schoolteacher's wife had her hand pressed to her chest. Behind them, at the far edge of the courtyard, Wenxi was aware of three figures standing quite still.

"I remember the sugar roses," said Chengyan, to his tea. "They were pink. One of them fell in the water and she cried about it for a week."

She could not speak. It was not in the script. It was not in any script. She had told him, once, that the cake had been a failure, that it had slumped, that she had never made one so bad. She had told it as a joke, years ago, at seventeen, and he had laughed, and not once, in all the years since, had he said that he remembered the roses.

She found her hand moving of its own accord. It crossed the little distance between them and took his, there on the bench, in front of twenty strangers. Her fingers laced through his. She did not decide to do it. It was simply the only thing her hand knew.

The watch ticked, and she felt him freeze.

"Two," he said, in a whisper.

"Interlaced," she whispered back. "That's two."

"That's all of them."

"For the day."

"Yes."

They sat there, fingers locked, with the whole group watching them, and the customs officer blew his nose with great violence and said, "Excellent tea."

They ought to have let go at the end of the five minutes.

They ought to have let go at the end of the tea. They ought, in strict honesty, to have let go at the end of the courtyard, when the visitors rose and shook themselves and began, in a rustle of straw hats, to move back toward the canal. But the visitors were still asking questions, and each question was a little harder than the last, and every time she thought of withdrawing, there were twenty pairs of eyes upon her and a pair of judges behind them, and her fingers refused.

"How long have you been together?" said the youngest of the scarf girls.

"Seven weeks," said Wenxi, which was true.

"Seven weeks! It looks so much longer."

"It feels, " said Wenxi, and found that she did not know what it felt like. "It feels like it has been going on for years."

Her hand tightened. She felt the answering pressure at once, strong and steady, and then she felt, with a small, startled thrill that went all the way down her spine, his thumb move across the back of her knuckles in one long, slow, deliberate stroke.

He was not looking at her. He was looking straight ahead, with his jaw set and his eyes on the water. But he did it again.

They walked the last stretch of canal in a kind of haze. She could not have said what she talked about. She remembered that a child asked whether the swans were real, and that she said they were geese, and that a woman asked if there was a legend, and that she said there was always a legend, and that Chengyan, to everyone's surprise, told one: the story of a carpenter and a cake maker who had built a bridge out of wood and sugar, and who lived on it for a thousand years because neither of them could decide which side to go home to. He told it badly. He told it in a dry, flat, deadpan voice, with enormous seriousness, and the schoolteacher laughed until he coughed.

She did not look at the watch. She did not think about the clause. She walked beside him in the slanting light with her hand in his, and her own heartbeat was so loud in her ears that she thought the whole party must hear it.

At the bridge, the visitors stopped. They arranged themselves in a ragged semi-circle, and raised their cameras, and called out, "Together! Closer! Smile!"

Chengyan lifted his wrist.

He looked at the cracked glass of the old steel watch. She saw his brows go down, slowly, and then up again, and then a very peculiar expression crossed his face, one of mild, stunned, baffled calculation, like a man who has measured a plank three times and arrived each time at a different answer.

"What?" she murmured.

"Nine minutes," said Chengyan, under his breath. "Past the first. And eleven, past the second."

She stared at him.

"We've broken it," he said. "Clause Three. Both of them. Twice."

"We have not."

"We have. I have it on the watch."

"We were, " she said, "in the performance. It was strictly necessary to the performance."

"Is that an exception?"

"It's an interpretation."

He made a small sound, half a laugh and half something else, and shook his head. His grip did not loosen. If anything it grew firmer, and she became aware that they were both standing there beneath the willow, hand in hand, perfectly still, having just agreed that they were in breach of contract, and neither of them had moved an inch.

The cameras clicked. A child cheered. Behind the semi-circle of visitors there was a smatter of applause, and she saw the retired teacher touching his handkerchief to his eyes, and the stout lady from the tourism board writing in a small book with an expression of great contentment.

Shen Haoran was not writing.

He stood a little apart, with his notebook under his arm, and his face was calm, but he was looking at their joined hands. He looked at them for a long moment, with the slightly absent gaze of a man who has seen something that reminded him of something else. Then his eyes lifted to hers, and he smiled, quietly, and inclined his head.

It was the smile of someone who recognises a thing and does not intend to say so.

The bus left at noon, in a cloud of exhaust and waving hands.

They stood in the empty street, after, in the hot bright quiet. The judges had gone. Tang Rui had gone, with a cryptic remark about the nature of scores. The canal slapped at the steps. She stood with her arms folded and her hair coming down, and he stood beside her with his hands in his pockets, and neither of them knew what to say.

"That went well," said Wenxi, finally.

"Yes."

"The flood. I didn't know you remembered the roses."

He took out a folded sheet of paper from the pocket of his shirt. It was creased and softened with handling, and she realised with a jolt that it was a copy of the contract, a pocket one, in his own small square hand. He unfolded it. He took the carpenter's pencil from behind his ear. And with the same grave, unhurried precision with which he marked a joint, he drew a single straight line through Clause Three.

"What are you doing?" said Wenxi.

"Recording the breach."

"You're striking it out."

"I am noting that it has been exceeded." He looked at the line, and then at her, and there was a gleam in his eye that she had not seen since he was nineteen. "It's a very honest document. It should be accurate."

She tried to be stern. She could not do it. The laugh came up in her chest and spilled out and she put both hands over her face, and when she took them away he was smiling too, a small, crooked, private smile, and the street seemed to tilt very slightly under her feet, like a boat leaving a quay.

She counted her hand that night.

It was a stupid thing to do. She sat on the edge of her bed in the little room with the rabbit stain on the ceiling and held it up in the lamplight, palm out, as though it belonged to somebody else. It was a small hand. It had a burn on the thumb from the oven and a scar from a sugar knife. It had been held for nearly twenty minutes that day, and there was no mark on it at all.

But it was warm. It had been warm for hours. It was warm in the way a stone is warm when the sun has been on it, and she folded her fingers into her palm to keep the feeling from escaping, and thought, quite clearly, I am in trouble.

Her phone buzzed on the pillow.

It was a message from Zhaoyu. There was no text. There was only a photograph, taken from some angle she could not place, probably from behind a flowerpot, in perfect focus. It showed the bridge, and the willow, and two people standing beneath it with their hands clasped. The woman was laughing. The man was looking at her. And somebody had put a very small yellow heart in the corner.

Beneath it, a moment later, a second message arrived.

For the spreadsheet, wrote Zhaoyu. Column F is called Evidence.