The hammer rang once. A spark jumped off the anvil and did not go out. It waited. They followed.

Jonah's grandfather died in April, a week before his ninetieth birthday, and in October the school announced that it was building a new display for the seventieth-odd anniversary of the flood.

Everyone in town knew about the flood. On the last night of January 1953 a storm drove the North Sea up over the sea wall, and by morning the lower streets by the harbour were under water to the bedroom windows. Every family in the old part of town had a flood story. Most of them had been told so often that they had worn smooth, like the steps of the church.

Jonah's family story went like this. Walter Fenn, seventeen years old, an apprentice at the boatyard, heard the screaming from the harbour streets, took a rowing boat from the yard without asking anybody, and rowed it back and forth through the flood until dawn. He saved six people. He never got a medal, because the medal went to somebody else. He never complained. He told the story every Christmas, after the pudding, and at the end he always said the same thing: You do what's in front of you.

Jonah was in Tara's year. He was a big, quiet boy who played rugby badly and drew beautifully, and since April he had been quieter than usual. When the history department asked students to bring in family flood stories for the display, he brought his grandfather's in a plastic wallet: a photograph of a thin young man in a flat cap, standing by an upturned boat, and a sheet of paper in Jonah's own neat handwriting.

Walter Fenn, aged 17, who saved six people in the flood of 1953.

"That's what I want on the wall," he said. "That's all."

The history teacher, Mr. Okafor, read it twice. He had taught Jonah's father, twenty-five years ago, and he had been to the funeral in April. Then he said, very gently, "Jonah, can I show you something?"

He took Jonah to the corridor by the hall, where the town's old flood plaque hung. It was bronze, green at the edges, and it had been put up by the council in 1954. Tara was helping Mr. Okafor with the display after school, so she was there, holding a box of drawing pins.

The plaque said: In grateful memory of the courage shown on the night of 31st January 1953. And in particular of ARTHUR BELL, postman, for gallantry in the rescue of townspeople from the flood.

There was no Walter Fenn on it anywhere.

By the end of the week, the whole of Year Twelve had an opinion.

It had started because Mr. Okafor, who was a careful man, had also gone to the town library and found the local newspaper for the week after the flood. It was a short report on page three, under a photograph of the harbour with only the chimneys showing.

Two women were pulled from the water in Ferry Lane on Sunday night by Mr. Arthur Bell, a postman, and a youth named W. Fenn, an apprentice at Harker's boatyard. Both women were taken to the cottage hospital and are said to be recovering.

Two. Not six.

Somebody photographed the newspaper report and somebody else shared it, and by Thursday lunchtime the common room had split down the middle.

"It's his grandad," said a girl called Nell, quite fiercely. "His grandad who's just died. You don't stand there with a newspaper and tell him his grandad was a liar."

"Nobody said liar," said a boy called Theo. "But the newspaper was there at the time. The family story's been told every Christmas for seventy years. Of course it got bigger. Stories do. It says two. Put two."

"Newspapers get things wrong all the time."

"So do families."

It went round and round. Tara noticed that nobody on either side had actually looked at anything except the one source that agreed with them. Nell's side talked about Walter. Theo's side talked about the newspaper. Neither side talked about the plaque, which did not seem to fit anybody.

Cosimo had been listening from the windowsill. He was a history student who did his coursework on the floor of his bedroom, with every document laid out round him in rows, and his friends complained that you could not walk into his room without treading on the sixteenth century.

"Can I ask something?" said Cosimo. "Has anyone got all of it? Every source, I mean. Not just the one you like."

"There's only two," said Theo. "The family and the paper."

"Three," said Tara. "There's the plaque."

"And there might be more," said Cosimo. "Lay them side by side before you choose. Pick the one you like best and you'll just find out what you already thought." He slid off the windowsill. "Where do they agree? That's the first question. Not which one's right."

Nell looked at him suspiciously. "Whose side are you on?"

"The paper's," said Cosimo, and grinned. "All of it. Every piece."

On Saturday Tara went with Jonah and Danya to the county record office, because Bartholomew volunteered there and had said, on the phone, that he would be "absolutely delighted, really, genuinely delighted".

He was. Bartholomew was a student archivist with careful hands and a cardigan that looked older than he was, and he met them at the door as though they were the most interesting thing that had happened all week. He had already found the newspaper's original bound volume and the council minutes for 1954. He laid them out on a long table under a lamp.

"Before we read a single word," he said, "look at the date. Who made this, and when, and why? Every source was written by someone for something."

He started with the newspaper.

"Second of February, 1953. Two days after the flood. Which sounds very close to the truth," said Bartholomew. "But closer in time isn't the same as closer to the truth. Look at the photograph credit. Taken from the railway embankment. Now look at this." He turned to the next column, where the reporter described his own night. Your correspondent, unable to reach the lower town, spent the night at the railway station, where the rescued were brought.

"So he wasn't in Ferry Lane," said Danya.

"He wasn't anywhere near it," said Bartholomew happily. "He was at the station, writing down what people told him as they arrived. Two women arrived at the station, wet and frightened, and said a postman and a boy had pulled them out. So that's what he wrote. He couldn't write about anybody who didn't come to the station."

Then the council minutes. Bartholomew turned the pages with the tips of his fingers.

"Here. March 1954. Resolved, that a plaque be placed in the school in memory of the flood, and that the gallantry of Mr. Arthur Bell, of the council's postal service, be particularly recorded." He looked up. "Who made the plaque? The council. And who was Arthur Bell? Someone the council employed. They could vouch for him. They had his name, his record, his supervisor's report. They didn't have a boatyard apprentice's name on any form." He tapped the page gently. "That doesn't mean they were unfair. It means they wrote what they could prove, about someone they knew."

"So the plaque's wrong too," said Jonah.

"Not wrong," said Bartholomew. "Partial. Turn it over. What's on the back? There's always a back."

Jonah was quiet for a long time. Then he said, "My great-aunt kept a diary. Walter's sister. Dad's got it in a box."

Bartholomew went very still, in the way some people go still when someone mentions cake.

"Written when?" he said.

"I don't know. I've never read it."

"Who made this, and when, and why?" said Bartholomew softly. "Can you find out?"

On the way home Tara worked out the dates on the back of a bus ticket. Walter had been born in 1936. The flood was in 1953. Seventeen. That part, at least, everyone agreed on.

The diary came to school on Monday in a biscuit tin.

It was a small red notebook belonging to Margaret Fenn, aged fourteen in 1953, and the entry for the first of February was written in pencil, very fast, with a lot of crossings-out. Jonah had not been able to read it on his own. He asked Tara and Cosimo to read it with him in the history room at lunchtime.

Cosimo did what Cosimo always did. He cleared a space on the floor, moved three chairs, and laid everything out side by side: the newspaper report, the plaque wording copied onto a card, the council minutes, Jonah's sheet of paper with the family story, and the diary, open at the first of February.

"Lay them side by side," said Cosimo. "Then put the disagreements in the middle."

Margaret's entry said:

Walter came back at six this morning soaked to his waist and could not stop shaking. He and Mr. Bell the postman got two ladies out of the water in Ferry Lane and Mr. Bell took them up to the station. Then Walter went back on his own with the boat because he heard children. He got the two little Ashby girls off the roof of the coal shed. Their mother was already out. He is asleep now. Mum says not to wake him. I am so proud I could burst.

Nobody said anything for a while.

"Where do they agree?" said Cosimo finally, very quietly.

He moved the cards with one finger.

"Newspaper: two women, Ferry Lane, Bell and Fenn. Diary: two women, Ferry Lane, Bell and Walter. That's two sources, and they agree." He looked up. "Did they copy each other, or see it themselves?"

"The paper was at the station," said Danya. "Margaret was at home. She couldn't have read it. It came out the next day."

"Then they didn't copy," said Cosimo. "Two separate witnesses. One source is a clue. Two that agree is a start." He moved another card. "Then the diary adds two more: two children off a coal-shed roof, after Bell had gone. The newspaper doesn't have them. Why not?"

"Because they never went to the station," said Tara. "Margaret says their mother was already out. They'd have gone to her, not to a reporter."

"So the newspaper didn't get it wrong," said Cosimo. "It just couldn't see it." He laid the two cards together. "Two women and two children. Four."

Jonah was looking at the diary, at the line I am so proud I could burst.

"Four," he said. "Not six."

"Four with two witnesses for the first two, and one witness for the second two," said Cosimo carefully. "Six only in the Christmas story."

"So he did make it up," said Jonah. His voice was not quite steady.

"I don't think anyone made anything up," said Isabeau.

She had come in halfway through and had been sitting on the radiator with her chin on her knees. Isabeau was a debater who practised by arguing whichever side she disagreed with, and she said it made her more interested in people's reasons than in who was winning.

"Can I ask the question I always ask?" she said. "Where was each teller standing? What could they actually see from there? And what did they want people to remember?"

She counted on her fingers.

"The reporter was standing at the station. He could see who arrived. He wanted to tell the town who was safe. He got that right." Another finger. "The council was standing in an office a year later. It could see its own staff records. It wanted to thank someone it could name and stand behind, and Arthur Bell really was brave. It got that right too. A true story can still leave things out."

"And Margaret?" said Tara.

"Margaret was standing in a kitchen at six in the morning with her soaking brother shaking by the fire. She saw him come home. She wanted to remember being proud." Isabeau smiled a little. "She wasn't writing for anyone. That's why it's so good. Nobody was ever meant to read it."

"And Grandad?" said Jonah.

Isabeau looked at him properly.

"Your grandad was standing at a Christmas table, every year for seventy years, telling a story to people he loved," she said. "Whose story is this, and whose is missing? It's his story. And it grew. Not because he lied. Stories that get told a lot change. People remember the feeling and the numbers drift toward it. Maybe someone once asked 'how many?' and he said 'oh, six or so,' and after that it was six. Maybe there were more people in the water that night who he tried to reach and couldn't. We'll never know." She paused. "And the bit he said at the end, every time? You do what's in front of you. That's in the diary too. He went back alone because he heard children. That's exactly what's in front of you."

Jonah put his head down on his arms for a moment. Nobody said anything. Danya, who was twelve and did not always know what to do, quietly moved the biscuit tin closer to him, as if that might help. It did a little.

"There's one more thing," said Isabeau. "The plaque. Who's missing from it? Walter. The Ashby girls. Margaret, who was proud. The women's names, even. Every account is told from somewhere."

"So which one's true?" said Danya.

"Bits of all of them," said Cosimo. "And the bits where they agree are the bits I'd put my name to."

On Thursday Mr. Okafor had to send the display wording to the printer. The panel would hang in the corridor beside the old plaque, and it would stay up for years. Students would walk past it every day. Jonah's father and mother were coming to the opening.

He was not a villain in any of this, and Tara knew it. He had taught Jonah's father. He had stood at the back of the church in April. He also had a head of department who had said, firmly, that a school display must not contain anything the school could not stand behind, and an email from a retired councillor who wanted to know why anyone was "rewriting the plaque". And he had promised Jonah, in October, that his grandfather would be on the wall.

He called them into the history room after school. All of them: Bartholomew, who had come over from the record office with a photocopy of the council minutes; Cosimo, with his cards; Isabeau on the radiator; Danya at the end of the table with a felt-tip pen; Jonah, holding the biscuit tin. Tara was pinning flood photographs to the display boards, because that was her job.

"I've read everything you found," said Mr. Okafor. "The paper, the minutes, Margaret's diary. Jonah has told me he's happy for us to quote it." He looked at the blank space on the panel. "I've got sixty words. One name, possibly two, and a number. Or no number. And it has to be right, and it has to be kind, and it has to stay up there for years."

He rubbed his eyes.

Then he looked across the room.

"Tara," he said. "You've been at this board every afternoon for a month. You've read all of it. You haven't said a word about the wording. You never do." He held out the pen. "What should it say?"

The history room went quiet. The radiator ticked. Out in the corridor the old bronze plaque caught the last of the light.

Tara thought of the reporter at the station, writing down only who came through the door. The council, thanking the man it knew. Margaret in the kitchen at six in the morning, too proud to sleep. The two little Ashby girls on the coal-shed roof, who had grown up and grown old and, somewhere, might have grandchildren of their own. Walter at the Christmas table, the number drifting a little higher every year. Jonah, holding a biscuit tin.

Everyone in the room was partly right.

Tara opened her mouth.

 

 

(Write the sentence Tara says.)

 

The spark dimmed to a warm dot and settled back on the anvil. The Green was just the Green again.

Back on the Green

At the next Green supper Danya asked Bà Tư to tell the story about the cart again, the one she had ridden when she was eight.

Bà Tư told it. Halfway through, Danya held up his hand.

"Last time," he said, "you said there were three bridges. This time it's four."

Bà Tư laughed so much she had to put down her spoon. "Then one of them is a bridge I added," she said. "Write the story down, little one, before I add a fifth."

Danya did. He dated the page, and on the back he wrote: Told by Bà Tư at supper. She thinks it might be three.

Afterword. The idea in this case is about sources and memory. Historians ask of every source who made it, when, why, and what that person could actually have seen; and they look for independent sources that agree, because agreement between people who did not copy each other is the firmest ground there is. Psychologists have shown since the 1930s, beginning with Frederic Bartlett, that honest memories change as stories are retold, usually toward a better story, without anyone lying. Neither fact makes family stories worthless. Sometimes, as in this case, they are the only reason the real evidence was kept. You can practise reading sources side by side in ArchiveQuest.