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

It was the longest day of the year, and so hot that the tar between the paving stones round the Green had gone soft. Inkling was lying on her back under the chestnut tree with her notebook on her chest, watching the leaves move, when the hammer rang. She sat up so fast that her notebook slid off into the grass.

She had three score sheets now, pressed flat in the back cover: the Opera Game, Légal's Mate, and the Immortal Game, with the Captain's little bracket and question mark beside its last three moves. Three of four. All spring she had been waiting for the fourth.

She picked up the notebook, brushed off a beetle, and followed the spark.

The road to the Slow Lake was dusty and white in the heat. The hedges were full of dog roses and bees. A farmer was cutting hay in a field beside the road, and the smell of it came over the hedge in warm waves. At the top of the last hill, Inkling stopped, as she always did.

The lake was blue. She had never seen it blue before. In autumn it had been silver, in winter white and grey, in spring a wild brown-silver. Now, under the midsummer sky, it was as blue as a cornflower, and there were boats on it, little ones with white sails, and children swimming off the jetty by the bakery.

The spark drifted down the hill toward the village. But it did not go to the academy this time. It went past the long low hall with the chequered roof, along the shore, and through a gate in a hedge into the garden behind Sir Pinwell's library, where it settled on the brass handle of a garden door.

Inkling had never been in the library garden. The gate's latch had broken once and been mended with a twist of wire, and on the gatepost beside the wire somebody had scratched a tiny hammer.

Inkling stopped. She took out her notebook and turned back through it. The hinge on her grandmother's chessboard. The bracket under the oldest shelf in the library. The iron band on the lamp post in the square. The same small hammer every time, and never a name.

"Who was here before us?" she said, to nobody in particular.

Nobody answered. The spark was waiting on the door handle. She opened the gate and went in.

The garden was long and green and full of shade. There were apple trees, and a sundial, and a pond with a fountain shaped like a fish. And in the middle of the lawn, laid out on the grass in squares of light and dark turf, was a chessboard as big as the one in the academy hall.

"We moved it," said Captain Castle, from a deckchair at the edge of the board. He was wearing a straw hat over his battlements. "Too hot for the hall. Sir Pinwell has lent us his lawn for the summer. The squares are cut into the grass. The gardener is not pleased."

"Is this for the last game?" asked Inkling.

"The last of the four," said the Captain. He sat up. "At the end of the month the village holds its Midsummer Garden Party on this lawn. Lemonade, strawberries, a brass band, and at sunset, on these squares, the Evergreen Game."

The children were arriving behind her, in sun hats, with bottles of water. The boy who knew a great many names had brought a fishing net for no reason anyone could work out.

"Why is it called evergreen?" asked the girl by the window. She was wearing a hat with cherries on it.

"Because it never gets old," said the Captain. "It was played more than a hundred and seventy years ago, and people are still finding new things in it. Like a tree that keeps its leaves all winter." He looked at Inkling. "Prompter. You have learned three things so far. Tell them."

Inkling took a breath. "Wait one move before you name a pin," she said. "Wait a long time before you name a winner. And before you take something free, ask why it's there."

"Good," said the Captain. "Here is the fourth, and it is the hardest. In this game, near the end, there is a chain of moves, one after another, each one forcing the next. Every one of them is a check. If you see the whole chain, the game is won. If you see only the first link, it looks like madness."

"So I have to see the end before I get there," said Inkling.

"You have to see the end before you call the first name," said the Captain. "That is what makes a prompter into a player."

That evening, when the heat had gone out of the day and the swallows were flying low over the lawn, the Captain told her the story.

"You remember Anderssen," he said. "The schoolteacher who won in London. The Immortal Game."

"The one who gave away everything," said Inkling.

"The same man," said the Captain. "A year later he was at home in Germany, and he played a friendly game in Berlin against a friend of his called Jean Dufresne. Dufresne was a strong player and a writer about chess. It was probably an informal game. The two of them sat down, and Anderssen played White, and twenty-four moves later he had played one of the most beautiful finishes in the history of the game."

"Did he give everything away again?"

"Not everything," said the Captain. "But at the end he gives up a rook, and then his queen, one after the other, both with check. And then the bishops finish it, check after check." He smiled. "The name came much later. Another great player, Steinitz, gave it the name after Anderssen had died. He was writing notes on the game, and when he came to one particular move, a rook move near the end, he wrote that it was an evergreen in the laurel crown of the departed hero."

Inkling wrote it down. Evergreen. Named by Steinitz, after Anderssen died.

"Is anything not certain?" she asked. She had learned to ask.

The Captain laughed. "You know me too well. Two things. First, when the game was first printed, the magazine did not print the last moves. It just said: White mates in four moves. In those days players often announced a mate instead of playing it out, the way you might say 'checkmate in two' and your friend would look and agree. So the last four moves we play are the ones everyone agrees must have been meant. But nobody wrote them down at the time."

"And the second?"

"The second is more interesting," said the Captain. "For a long time everyone believed Black was lost, whatever Black did at the end. Then later players studied it, very carefully, and found that Black had a better defence at one point. If Black had found it, the game might have been a draw." He shrugged. "Black did not find it. Anderssen did not have to worry about it. But we will tell the village, because it is true."

Inkling wrote: First printing said "mates in 4". Last moves not written down. Later players found a defence that might draw. She looked at the list. Every one of the four games had something like this. A rook nobody was sure about. A mate that might not have been played. A night nobody wrote down.

"Is any famous game exactly true?" she asked.

"The moves usually are," said the Captain. "It's the stories round them that grow."

The next morning the faculty arrived on the lawn, and there were more of them than ever.

Captain Castle was there already in his deckchair. Merle the Gleaner came up from the low end of the lake with an empty basket. "Strawberries," she said hopefully. "Somebody always drops strawberries at a garden party." Kester the Finisher sat down under an apple tree with a bag of biscuits.

Then came the twins, Gable and Garrett, the walking towers, who arrived one behind the other as they always did.

"One of us goes first—" said Gable.

"—and the other comes behind," said Garrett.

Then the Twin Knights of Fork Hill arrived. Inkling had heard of them but never met them. There were two of them, and they did not walk onto the lawn. They appeared on top of the garden wall, standing up, side by side, though there was a sign on the wall that said PLEASE DO NOT STAND ON THE WALL.

"You see one target," said Knight One, looking down at the chessboard.

"We see two," said Knight Two.

"Get down off the wall," said Captain Castle, without looking up.

"No apologies," said Knight One cheerfully, and neither of them got down.

After the twins came a nightingale, small and brown, who did not land on the lawn at all but settled in the branches of the biggest apple tree. She said nothing. She just sat there, and after a moment Inkling realised that every bird in the garden had gone quiet and turned toward her, the way people turn toward music.

"Siren Lyra," said the Captain quietly. "She sings from the branch she wants you at."

Last of all came two tall thin women in matching dark-green tunics, with small grey clasps in their hair. They walked through the gate in step, one half a pace ahead of the other. They were identical. Inkling could not tell them apart at all, until she noticed that the one in front wore her clasp on the left and the one behind wore hers on the right.

"Veil," said the one in front.

"And Vow," said the one behind. "You saw me. You didn't see her."

"Look behind the one who moves," said Veil.

Inkling counted. Seven teachers. Seven names to call, in the right order, at the right moments, in a chain where every move forced the next.

She wrote their names down the side of her page, one under the other, and drew a long line beside them. She did not yet know what order they would go in.

The first rehearsal began in the morning, before the heat got too bad. The Captain played the opening himself, walking slowly across the grass squares in his straw hat.

White pushed the king's pawn two squares. 1. e4. Black did the same. 1... e5. White brought out a knight, attacking the black pawn. 2. Nf3. Black brought out a knight to defend it. 2... Nc6. White's bishop came out to c4, aiming at f7. 3. Bc4. Black's bishop came out to c5, aiming at f2. 3... Bc5.

"Everything so far is what everybody plays," said the Captain. "Now watch."

White pushed a pawn on the queen's side two squares, to b4, right in front of Black's bishop, where the bishop could simply take it. 4. b4.

"Another gift!" said the girl in the cherry hat. "Like the King's Gambit!"

"Very like it," said the Captain. "This one is called the Evans Gambit. White offers a pawn to gain time. If Black takes it, White can push another pawn to the middle with tempo."

Black's bishop took the pawn. 4... Bxb4. White pushed the c-pawn one square, attacking the bishop. 5. c3. The bishop stepped back to a5. 5... Ba5. White pushed the d-pawn two squares into the middle. 6. d4. Black took it. 6... exd4.

Inkling looked at her two columns. MATERIAL: White was two pawns down. IN PLAY: White had two pawns in the middle, a bishop aimed at f7, a knight, and the king ready to castle. Black had a knight, a bishop off on the edge at a5, and a pawn that had wandered into White's half.

"White's behind," she said. "But White's got more pieces out."

"The same story as the Immortal Game," said the boy with the fishing net.

"The same story," said the Captain. "Anderssen liked it."

"And now," said Captain Castle, "it is my move."

He got up from the deckchair and took off his straw hat and put it on the sundial. Then he walked to the white king on e1, and the white rook on h1, and stood between them with one hand on each.

"Tuck the king in and bring the rook out," he said. "Everyone comes to the party."

He moved the king two squares toward the rook, to g1, and lifted the rook over it to f1. 7. O-O.

"Castling," said the boy with the fishing net. "Short side."

"The king is safe in the corner behind his pawns," said the Captain, putting his hat back on. "And the rook is one step nearer the middle, where the work will be. One move, two jobs. I have always liked that."

"Black hasn't castled," said Inkling.

"No," said the Captain. "And now notice something. Black's king is still in the middle of the board on e8. As long as it stays there, every open line in the middle points at it." He sat back down. "Count the kings, not just the pieces. A king in the middle is a king with a lot of doors."

Black pushed the pawn on d4 one more square forward, to d3, deep into White's position. 7... d3.

"That pawn is very brave," said the girl in the cherry hat.

"That pawn is a long way from home," said Merle, from the shade. "Is anybody coming back for it?"

Inkling wrote both remarks down. She was beginning to think that Merle's question was one of the most useful sentences anybody had ever said to her.

The next few days of rehearsal went slowly, in the heat, a few moves each morning.

White's queen came out to b3, looking at f7 through the bishop. 8. Qb3. Black's queen came out to f6, defending it. 8... Qf6. White pushed the e-pawn forward, attacking the queen. 9. e5. She stepped to g6. 9... Qg6. White's rook came to e1, behind the pawn. 10. Re1. Black's other knight came out to e7. 10... Nge7.

White's dark-squared bishop came out to a3, looking right down the long diagonal toward e7. 11. Ba3. Black pushed the b-pawn two squares. 11... b5. White's queen took it. 12. Qxb5. Black's rook came across to b8, attacking the queen. 12... Rb8. The queen stepped to a4. 13. Qa4. The bishop on a5 stepped back to b6. 13... Bb6.

White's last knight came out to d2. 14. Nbd2. Black's queen's bishop came out to b7. 14... Bb7. White's knight jumped to e4, toward the black king. 15. Ne4. Black's queen went to f5. 15... Qf5. White's bishop took the brave black pawn on d3. 16. Bxd3. Black's queen went to h5. 16... Qh5.

Every morning Inkling filled in her two columns. Every morning they said the same thing. Material was even now; White's queen had taken back one gambit pawn on b5, and the bishop had taken the brave pawn on d3. But IN PLAY was another matter. Every white piece was out. The white king was safe in the corner. Black's king was still sitting on e8, in the middle, uncastled.

"Black's queen keeps moving," said the boy with the fishing net. "Like in the Immortal Game. She's been on f6, g6, f5 and h5."

"She has," said the Captain. "And Black's king has been on e8 the whole time. One of those pieces should have moved more and the other less."

Inkling looked at the black king on e8. In front of it, on e7, stood a black knight. Next to it, on d7, a black pawn. On the long diagonal from a3, the white bishop was pointing straight at the knight on e7.

She felt something stir, the way she always did a move or two before she understood a thing. She did not name it. She drew a small circle round e7 in her notebook, and waited.

On the hottest afternoon of all, too hot to rehearse, the Captain gathered the children in the shade and made them count.

"Count the pieces in play, not the pieces on the board," said the Captain. "We have done this in every game. Let us do it properly, one last time. Everyone comes to the party. The question is who has arrived."

He pointed at the white pieces on the lawn, one at a time, with his straw hat.

"The king, tucked in behind his pawns. Arrived," said the Captain. "The rook that came with him when we castled, and then moved over to e1. Arrived. The queen on a4. Arrived. Both knights. Arrived. Both bishops. Arrived." He stopped at the corner. "And the rook on a1. Still in the hall with its coat on."

"So White's got one piece still to come," said the girl in the cherry hat.

"Now Black," said the Captain. "Take your time. The board will wait."

The children counted. The black queen on h5, out and about. The bishops on b6 and b7, out. A knight on c6 and one on e7, out. A rook on b8, out of the corner at least.

"And the king," said Inkling. "Still on e8. Still in the middle. And the other rook, on h8, behind him, stuck."

"A king in the middle is a king with a lot of doors," said the Captain. "Count the doors. How many open lines are pointing at e8 right now?"

They counted. The e-file, from the white rook on e1, though the knight on e7 was standing in it. The diagonal from the bishop on a3, aimed at e7 as well. The diagonal from the queen on a4 through c6 and d7 to e8, though the knight on c6 and the pawn on d7 were standing in it.

"Every door has something standing in it," said Inkling. "The knight on e7, the knight on c6. If those knights ever move..."

Merle, lying in the shade with her basket over her face, lifted a corner of it.

"Nobody's guarding that one," she said sleepily, about nothing in particular. "Free is free." Then she put the basket back down.

"Merle is right without meaning to be," said the Captain. "The black king is guarded by pieces that are also standing in doorways. Each of them is doing two jobs at once. And the guard cannot be in two places, as a friend of mine likes to say." He fanned himself with the hat. "Take your time, prompter. When the last white rook arrives at the party, watch which doorways it is looking through."

"Twin Knights," said the Captain. "Your move."

The twins jumped down off the garden wall, at last, which made the Captain sigh with relief, and walked onto the lawn. They went to the white knight on e4.

"You see one target," said Knight One to the children.

"We see two," said Knight Two.

"One hop, two prizes," they said together.

The Captain jumped the knight from e4 to f6. 17. Nf6+.

"Check!" said the girl in the cherry hat.

"And," said Knight One, pointing.

The children looked. The knight on f6 gave check to the black king on e8. But it also attacked the black queen, on h5.

"Pick one to save," said Knight Two politely. "We take the other."

"That's a fork," said the boy with the fishing net. "King and queen."

"Except the king has to be saved," said Inkling slowly. "You always have to get out of check. So Black can't save the queen. Unless..." She looked. A black pawn on g7 could take the knight. "Unless the pawn takes it."

Black's pawn took the knight. 17... gxf6. White's pawn took back. 18. exf6. Black's rook came from h8 to g8. 18... Rg8.

"So the knights gave themselves away," said the small boy at the back.

"No apologies," said Knight One. "We were never going to get both. But look what we got instead."

Inkling looked. The g-file was open now, which was good for Black's rook. But White had a pawn on f6, deep in Black's camp, right next to the knight on e7 and close to the king. And the black king had no pawns in front of it on the kingside any more. Nowhere to castle to. Nowhere to hide.

"You broke the wall in front of his house," she said.

"One hop," said Knight Two, climbing back onto the garden wall, "two prizes. The second prize was the wall."

"Now," said the Captain. "This is the move that Steinitz called evergreen. Gable and Garrett?"

The twin towers walked onto the lawn, one behind the other. They went to the white rook on a1, which had been sitting in the corner all game, the only white piece that had not moved.

"Straight lines only," said Gable.

"Open file, open road," said Garrett.

The rook slid from a1 to d1. 19. Rad1.

It did not give check. It did not take anything. It went to the d-file, behind the white bishop on d3, and stopped.

"Every white piece is in play now," said the Captain softly. "Every single one. The rook on d1 was the last to come to the party. And it has arrived at the right moment."

"But the black queen," said Inkling suddenly. "The queen on h5 can take the knight on f3. And then..." She looked at the white king in its corner, behind its pawns. On g2 was a white pawn. If the black queen came to f3, she would be looking at g2, and the black rook on g8 was looking down the open g-file at g2 too.

"Black's threatening mate," said Inkling. "On g2. The queen and the rook together."

"That's right," said the Captain. "So it's Black's turn. What will Black do?"

Merle got up out of the shade.

"I know what I'd do," she said. "There's a knight on f3, and nobody's guarding that one. And if I take it, I'm threatening mate as well. That's two things at once. That's the best kind of free."

She walked onto the grass board in the sun and stood beside the black queen on h5, and looked along the diagonal to the white knight on f3.

Then she stopped. Inkling saw her stop. She saw Merle look at the knight, and then, slowly, at the black king on e8.

"Is anybody coming back for it?" Merle said quietly. "Ask that first."

The garden was very quiet.

"I don't know," said Merle at last. "I can't see that far. But I can see mate on g2. And a free knight. So I'll take it." She smiled ruefully. "It's what happened, you know. That's the game."

The black queen took the knight. 19... Qxf3.

And Inkling, who had promised herself that this time she would see the end before she named anything, felt the words come up in her throat: White's going to be mated! Black's won!

She held them. She held them so hard that her ears went hot. She did not say them.

Instead she said, out loud, so that she could hear herself: "It's White to move."

"It is," said the Captain. "And when it is your move and the other side is threatening mate, there is only one kind of move that you are allowed to play, unless you are prepared to be mated."

"A check," said Inkling. "A move that forces him to answer. So he never gets time to mate."

"A check," said the Captain. "And then another. And then another. If they all force the answer, he never gets his move at all." He leaned back in the deckchair. "Take it home, prompter. Tomorrow you call the next name. But before you call it, you have to see every move from here to the end. All of them. Including the mate."

While Inkling was trying to see the end of the game, the sisters set up a small practice table under the apple trees for the children, with an ordinary board and only three pieces on it.

A white rook on a1. A white bishop on a4, on the same file, in front of it. And a black king, at the top of the file, on a8.

"Look at the board," said Veil. "Which white piece is attacking the king?"

"None of them," said the girl in the cherry hat. "The bishop's in the way of the rook."

"You saw me," said Veil, and she touched the bishop. "You didn't see her." She touched the rook.

Then Veil picked the bishop up and moved it off the file, diagonally, to d7.

The rook on a1 was looking straight up the empty file at the black king. Check.

"Look behind the one who moves," said Vow quietly. "The rook did not move at all. She was there the whole time. The bishop only stepped aside."

"That's a discovered check," said the boy with the fishing net.

"That is one check," said Veil. "Now we will show you two."

They put the bishop back on a4 and set the black king on d7 instead. Then Veil moved the bishop again, from a4 to b5. It was check from the bishop along its diagonal, b5, c6, d7. But the rook on a1 was not looking at d7 any more, because the king was not on the a-file.

"Not quite," said Vow. "The king has to be on the line behind, as well as on the line in front. Then both of us can check him at once."

The children moved pieces about until they found it. A rook on d1. A bishop on d3 in front of it. A black king on d7, on the same file. Then the bishop moves off the file to a square from which it also gives check, and both pieces are giving check at the same moment.

"Two checks with one step," said Veil and Vow together.

"Why does it matter if there are two?" asked the small boy at the back.

"Because the king can block one line, or capture one piece," said Vow. "But not two. Against two checks he cannot block and he cannot capture. He can only run." She smiled at Inkling, who had come to watch. "Remember where we put the pieces, prompter. A rook on d1. A bishop on d3. You will need to know where the king has to be."

Inkling looked at the practice board, and then across the lawn at the big one, where the white rook was sitting on d1 behind the white bishop on d3, exactly as on the little table. The black king was on e8.

The king has to come to d7, she thought. Somebody has to bring him there.

She did not say it. She wrote it in the margin, and drew an arrow from e8 to d7.

Inkling still could not see how anyone could make the king walk from e8 to d7. Kings do not go where you want them. So she went to find Siren Lyra, who lived in the reed-woods along the shore.

It was evening, and the reeds were full of birdsong. Inkling followed the loveliest voice until she found the nightingale on a branch above a small clearing, where three young rabbits were sitting in a circle on the grass listening to her.

"They came on their own," said Lyra, when she saw Inkling looking. "I wanted them here for a story. So I sang from this branch. Make one place the loveliest place to be, and wait."

"Doesn't that only work for rabbits?" asked Inkling.

"It works for anyone who wants something," said Lyra. "Which is everyone. Come and see." She flew to a different branch on the far side of the clearing and sang there instead, the same song, very softly. The three rabbits got up, one by one, and hopped across the clearing to sit under her new branch.

"I did not push them," said Lyra. "I never push. Let the wanting do the walking. They carried themselves here, happy the whole way."

"In the game," said Inkling slowly, "I need the black king to come to d7."

"Then what does the black king want?" asked Lyra.

Inkling thought about it. What does any piece want? To be safe. To take things. To win.

"He'd want to take a queen," she said. "If there was a queen next to him. Anyone would."

"Then put the loveliest thing in the garden on d7," said Lyra, "and he will come and take it. That square, there."

Inkling stood in the clearing with her mouth open.

"But I'd lose the queen," she said.

"You would lose the queen," agreed Lyra, "and he would be standing exactly where you wanted him. That is the bargain. It is only a good bargain if you know what happens next."

That night, at the kitchen table, Inkling worked out what happened next.

That night it was too hot to sleep. Inkling sat at the kitchen table in her nightdress with the window open and the moths coming in, and set the position out on the folding chessboard.

Her grandmother came down for a glass of water and stayed.

"The fourth one," said her grandmother. "The last one."

"I have to see the end before I start," said Inkling. "Every move, all the way to mate. And every one has to be a check, or Black mates me on g2."

Her grandmother sat down. "Then start with what you can see."

Inkling looked at the board. The black king was on e8. The black knight on e7 was guarding it. On d7 was a black pawn. The white rook on e1 was looking straight up the e-file at the knight on e7. The white bishop on a3 was looking up its diagonal at e7 as well.

"The rook can take the knight," she said. "With check. Rxe7. And then the knight on c6 takes the rook back. Or the king moves. But in the game, the knight takes it."

She moved the pieces. White rook to e7, black knight from c6 to e7, taking it.

"Now what?" said her grandmother.

Inkling looked. The black king on e8. In front of it now on d7, the black pawn. Her white queen on a4 was looking along the diagonal: a4, b5, c6, d7. The c6 knight had just left. The road was open.

"The queen takes d7," she said slowly. "With check. And the king has to take her."

"You'd give the queen away?"

"I think that's the point," said Inkling. "It isn't to win the pawn. It's to make the king come to d7." She did not know yet why d7. She moved the queen to d7 and the king took it.

Then she looked at the board and saw the white bishop on d3, and behind it on the same file, the white rook on d1. And in front of them both, on d7, the black king.

She sat very still.

"If the bishop moves," she whispered. "If the bishop steps aside, the rook gives check. And if the bishop gives check as well when it moves..."

"Two checks at once," said her grandmother, who had played a great deal of chess when she was young and had not mentioned it very often.

Inkling played the bishop to f5. Check from the bishop. Check from the rook behind it. The king had to move. It could go back to e8. Or, she checked, to c6. She tried both.

If it went to c6, the bishop went to d7 and it was mate.

If it went to e8, the bishop went to d7 with check. The king had to go to f8. And then the bishop on a3, the one that had been looking up the long diagonal all game, took the knight on e7.

"Mate," said Inkling. "Rook takes, queen takes, bishop, bishop, bishop. Five moves, and after the rook, it's mate in four." She counted on her fingers. "Every one's a check. He never gets to move his queen at all."

Her grandmother looked at the board for a long time.

"So who do you call first?" she asked.

Inkling looked at her list of seven names down the side of her page. She drew a line from the rook to Gable and Garrett. From the queen to Siren Lyra. From the bishop on f5 to Veil and Vow. From the last two bishop moves to Kester.

"All of them," she said. "In order. But I had to see the last one before I could call the first."

The next morning, in the cool before the heat, the whole faculty stood round the edge of the lawn, and Inkling called the first name.

"Gable and Garrett."

The towers walked onto the grass, one behind the other.

"One of us goes first—" said Gable.

"—and the other comes behind," said Garrett.

The white rook on e1 slid up the open e-file and took the black knight on e7. Check. 20. Rxe7+.

"Together we're twice as heavy," said Gable, "but sometimes one of us has to go first and not come back."

The black knight on c6 took the rook. 20... Nxe7.

"White's a rook down," said the girl in the cherry hat. "And Black's still threatening mate."

"Not if Black never gets to move," said Inkling.

She did not hesitate this time. She had seen the whole chain the night before, at the kitchen table, with the moths. She looked up into the apple tree.

"Siren Lyra," she said.

The nightingale flew down out of the apple tree and landed on the white queen on a4. She did not push it. She did not seem to do anything at all. She simply began to sing, very softly, and the Captain lifted the queen and carried it along the diagonal to d7, and took the black pawn, and set the queen down right next to the black king.

Check. 21. Qxd7+.

"Make one square the loveliest place," sang Siren Lyra. "Come and see, little king."

The black king could not stay where it was. It could step aside to f8. But there was a white queen right in front of it, the most valuable piece on the board, and the king could take her.

"Let the wanting do the walking," said Lyra.

The black king took the queen. 21... Kxd7.

"He took the queen!" said the small boy at the back, outraged. "Again! Everybody always takes the queen!"

"Of course he did," said Lyra gently, from the top of the d7 square. "Who would not come toward the loveliest thing in the garden? I did not make him. I only sang from the branch I wanted him at." She looked across the lawn at Inkling. "That square, there. Now, prompter. Who is behind the one who moves?"

Inkling looked at the black king on d7. At the white bishop on d3 in front of the white rook on d1. All three on the same file, in a line, like beads on a string.

"Veil and Vow," she said.

The sisters walked onto the lawn in step. Veil, half a pace ahead, went and stood behind the white bishop on d3. Vow, half a pace behind, stood behind the white rook on d1.

"You saw me," said Veil to the black king.

"You didn't see her," said Vow.

Veil stepped aside, and as she did the Captain moved the bishop from d3 to f5. Check, from the bishop, along the diagonal f5, e6, d7.

And with the bishop gone from d3, the d-file was open, and the rook on d1 was looking straight up it at the black king on d7. Check from the rook as well.

"Two checks with one step," said Veil and Vow together. 22. Bf5+.

"A double check," said the boy with the fishing net, very quietly, as if he were in church.

"Against two checks," said the Captain, "you cannot block, because you cannot block two lines with one piece. You cannot capture, because you cannot capture two pieces with one move. The king must move. That is all."

The black king stepped back to e8. 22... Ke8.

"He could have gone to c6," said Inkling, because she had tried it at the kitchen table. "But then the bishop goes to d7, and it's mate at once."

"Look behind the one who moves," said Veil, and the sisters walked off the lawn in step, Veil half a pace ahead, exactly as they had come.

"Kester," said Inkling.

The young hedgehog put down his biscuits and walked onto the lawn.

"Then I'll finish it," said Kester.

The bishop on f5 moved to d7, right next to the black king. Check. 23. Bd7+.

"Escape, block or capture," said Kester. "Block? Too close. Capture? The bishop's guarded by the rook behind it. Escape? Two squares, d8 or f8." He nodded. "It doesn't matter which. From either one, the next move is mate. In the game he went to f8."

The black king went to f8. 23... Kf8.

Then Kester walked all the way across the lawn to the white bishop on a3. It had come out on the eleventh move and had been sitting there ever since, looking up the long diagonal at the black knight on e7, through all the noise of queens and rooks and gambits. It had not moved again in twelve moves.

"Some pieces do one job for a very long time," said Kester, "and then they do it once."

The bishop on a3 swept up the diagonal and took the knight on e7. Check.

"Escape?" said Kester. "G7 is covered by the pawn on f6. E8 by the bishop on d7. G8 is his own rook. F7 is his own pawn. Block? Nothing. Capture? The bishop on e7 is guarded by the pawn on f6. Escape, block or capture. None of them."

24. Bxe7#.

"Done," said Kester.

The garden was absolutely silent. Even the bees seemed to have stopped. Then the Twin Knights, on top of the wall, started clapping, and everybody joined in.

Inkling looked down at her notebook. On the page, in the margin, she had written the five moves of the finish the night before at the kitchen table, before she had called a single name. They were exactly right.

After the rehearsal the Captain called the children together in the shade of the apple trees.

"Now I am going to tell you something uncomfortable," he said. "This game is evergreen, and beautiful, and every move of the finish is forced. But it did not have to happen."

"What do you mean?" asked the girl in the cherry hat.

"Go back to Merle's move," said the Captain. "When the queen took the knight on f3. For a long time everyone thought Black was lost whatever Black did there. But years later, players studied that position very carefully, and they found other moves for Black. One of them was to bring the rook on g8 down to g4, instead of taking the knight. With best play from both sides, they think that might have saved Black. A draw, perhaps."

"So the beautiful finish only works because Black made a mistake?" said Inkling.

"The beautiful finish only works because Black took the knight," said the Captain. "Which was a very natural thing to do. It was free, and it threatened mate. Merle's move. Everybody's move."

Merle, sitting under the tree with her basket, nodded slowly.

"Free, and threatening mate," she said. "Two things at once. The best kind of free." She sighed. "I asked the question, you know. Is anybody coming back for it? And I couldn't see the answer. So I took it anyway."

"That is not a failure," said the Captain. "Asking the question is right even when you cannot see the answer. Sometimes you will not be able to. The difference between Black here and Black in Légal's Mate is that Black here had no easy way to know. The trap was very deep."

Inkling wrote it all down: Later players found 19...Rg4 might draw. The finish is forced only after Qxf3. Then underneath: Seeing the end only works if you look at their best move, not just the one they played.

She looked at that last line for a long time. It was the most grown-up thing she had ever written in the notebook.

On the last afternoon before the Garden Party, the Twin Knights taught the youngest children a game of their own, from the top of the wall, because they would not get down.

They chalked a knight on a square of the path, and scattered paper cups on other squares round it.

"You see one target," said Knight One.

"We see two," said Knight Two. "Find a square where one knight hop hits two cups at once."

The children hopped about on the path trying knight moves, two along and one across, shrieking whenever a hop landed next to two cups. The boy with the fishing net found one that hit three, and the twins were so pleased they nearly fell off the wall.

"One hop, two prizes," said Knight One.

"Pick one to save," said Knight Two. "We take the other."

Inkling watched from the bench. In the game, the twins' fork had not won the queen. Black had taken the knight instead. But it had broken the pawns in front of the black king, and that had let everything else happen. The fork had not been the end. It had been the first strand.

"Is every move in the finish like that?" she asked Captain Castle, who was dozing in his deckchair. "Something that makes the next thing happen?"

The Captain opened one eye. "The good ones are," he said. "You have spent a year learning to wait before you name things. That was the right lesson. But there is a second half to it. Once you can see far enough, you stop waiting. You see the end, and then you go, and you don't stop to check each step on the way, because you already did." He closed the eye again. "Linnet would tell you the same. The first strand forces the second."

On the evening of the Midsummer Garden Party, the whole village came to Sir Pinwell's lawn.

There were trestle tables with white cloths, and jugs of lemonade with ice in them that clinked, and bowls of strawberries, and a brass band that played under the apple trees and was louder than the one at the Spring Fair and slightly more in tune. Children ran about with sparklers. Inkling's grandmother came in a straw hat with a flower in it, and sat in the front row of deckchairs with her folding chessboard on her knee.

The sun went down over the lake, red and gold, and the grass squares of the board turned long-shadowed. The faculty took their places round the edge. The Twin Knights stood on the wall. Siren Lyra sat in the apple tree. Veil and Vow stood side by side by the sundial.

Inkling stood beside the board with her notebook. She knew every move. She had known the end for weeks.

The opening went by. The Evans Gambit pawn was offered and taken. The Captain castled to applause. The queens moved and moved. The Twin Knights hopped into f6 and were taken. The last rook came to d1, and Inkling said, so that everybody could hear: "That move is the one that Steinitz called evergreen. Every white piece is in play now."

Merle took the knight on f3. A man in the front row said, "Oh dear, that's mate on g2," and several people nodded.

"Gable and Garrett," said Inkling.

The rook took e7 with check. The knight took it back. The man in the front row said, "Well, now White's a rook down as well."

Then Inkling did something she had decided to do at the kitchen table, and had not told anyone, not even the Captain.

She turned to face the audience, and she said: "White mates in four moves."

There was a murmur. Somebody laughed nervously.

"That's what the magazine said," Inkling went on, "when this game was first printed, in Germany, a hundred and seventy years ago. It didn't print the last moves. It just said: White mates in four. Players in those days used to announce a mate instead of playing it. So I'm announcing it. And now we'll play it, so you can check."

At the side of the lawn, Captain Castle took off his straw hat.

"Siren Lyra."

The nightingale sang, and the queen took d7 with check, and the king came to the loveliest square in the garden and took her.

"Veil and Vow."

The bishop stepped aside to f5, and the rook behind it gave check, and the bishop gave check as well. Two checks with one step. The king went back to e8.

"Kester."

The bishop went to d7 with check. The king went to f8. And the bishop on a3, which had been waiting all game, swept up the long diagonal and took e7.

"Mate," said Inkling. "In four."

For a moment the only sound on the lawn was the fountain. Then the brass band, which had not been asked to, struck up a march, and the whole village rose out of its deckchairs, and somebody's sparkler set fire to a strawberry.

Later, when the lanterns were lit along the hedges and the band had stopped and the strawberries were all gone, Inkling found the faculty sitting together on the library steps.

"You announced it," said Siren Lyra, who had come down out of the tree at last. "Before you played it. That was very brave."

"I'd already seen it," said Inkling. "There wasn't anything to be brave about. I knew it was there."

"That is what seeing the end is," said Linnet, who had come up from the willow-banks to watch and was perched on the hand rail. "Once you have seen the whole net, the first strand is not brave. It is just the first strand."

"Pick one to save," said Knight One, from the top of the library wall.

"We take the other," said Knight Two. "Well done, prompter."

Gable and Garrett sat side by side on the bottom step, one a little in front of the other. "One of us went first—" said Gable.

"—and didn't come back," said Garrett. "But the other came behind. And the queen. And the bishops."

Merle had found two strawberries somebody had dropped under a table and was eating them very slowly. "Nobody was coming back for these," she said. "I checked."

Sir Pinwell said nothing at all. He was writing in his notebook. Inkling leaned over to look. It said: She saw the end, and then she did not wait. That is the other half of the lesson. A year well spent.

"Hmm," said Sir Pinwell, and closed the notebook.

Then Captain Castle came down the steps with something under his arm. It was a small book with a green cloth cover, the same green as Inkling's notebook. On the front, in gold, it said: Inkling's Scorebook.

Inside, sewn into the binding, were four score sheets in his square, careful handwriting. Légal's Mate. The Opera Game. The Immortal Game. And the Evergreen Game, with the place and the year at the top, and beside the last four moves a small note: First printed as "White mates in 4". Announced again, Midsummer, by the prompter.

After the fourth sheet, the rest of the pages were blank.

"Four of four," said the Captain. "Those are other people's games. The rest of the book is for yours."

The spark was waiting on the brass handle of the garden door when Inkling finally went to go home. It was as bright as a candle now.

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 end of the summer there was a board-game evening in the church hall on the Green. Inkling played Beto at draughts, and halfway through she saw it: if she gave him one piece, he would have to take it, and then she could jump three of his in a row, and then he would have to take again, and then she could crown.

A year ago she would have shouted the moment she saw the first jump. Six months ago she would have waited so long checking everything that the moment would have gone.

This time she looked at all of it, to the end, once. Then she pushed the piece forward and didn't stop until she was done.

Beto stared at the board. "How did you see that?" he said.

"I looked at the last move first," said Inkling.

Then she went home and wrote the game on the first blank page of her scorebook, even though it was draughts.

Tell the story back to someone in your own words. Then set up a board, or draw one, and play the last five moves of the Evergreen Game with a grown-up. You take White. Before you play the first one, say all five out loud.