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

The spark led them to the bench under the big tree on the Green. Then it simply waited there.

Warm wind blew the Green away, and the ground under their feet was somewhere else, the day before.

They were standing on the shore of a lake so big they could not see the other side. Tall reeds grew in the shallow water. Green hills rose behind them. A little way along the shore was a camp of round huts made of branches and reeds, with a fire smoking in the middle.

A girl their age was standing at the water's edge. She was holding a basket shaped like a long bottle, woven from reeds.

"It's a fish trap," she said, when she saw them looking. "I set them all along the shore. In the reeds, by the big rock, and under the fig tree."

"Why are you bringing them in?" asked Lan.

"Tomorrow our camp moves along the lake," said the girl. "Every trap has to come in tonight. My grandmother and I took days to weave them."

Inkling looked at the trap, and at the shore, and she was sure she knew what the girl needed.

"I noticed it straight away," said Inkling. "What you need is called a..."

She said the word before she had looked properly.

Bzzz.

Inkling went pink. Lan squeezed her hand.

"The door," said Lan kindly. "Only the question."

"How many traps did you set?" asked Inkling.

The girl started counting on her fingers. She got to the end of one hand, and then the end of the other. Then she stopped.

"More than that," she said. "More than my hands."

They walked along the shore and brought in a few traps. By the big rock, the girl stopped again.

"Did I put three here, or four?" she said. "I can't remember."

Her grandmother came down from the camp. She listened, and nodded, and gave the girl a little leather bag.

"Put one pebble in for every trap you set," she said. "When a trap comes in, throw one pebble into the lake. When the bag is empty, the traps are all in."

It worked. For a while.

Then, by the fig tree, the girl slipped on a wet rock. The bag tipped over. The pebbles rolled into the shallow water and were gone.

"Now I don't know how many there were," said the girl. She looked as if she might cry.

Inkling did not name anything this time. She asked questions instead.

"I noticed something," said Inkling. "What was each pebble?"

"One trap," said the girl.

"So one thing for each trap worked," said Inkling. "That part was right. What went wrong?"

"The pebbles fell out," said Lan.

Inkling thought for a moment. "Wait, I can name it now," she said. "One mark for one thing. The mark just has to stay where you put it."

The sun was getting low over the lake. Some traps were in and some were still out, and nobody knew how many were left.

The girl sat on the shore with her knees pulled up. "It's hopeless," she said.

Lan looked at the old bones by the fire, where people had been making tools.

"Could the marks be cut into something?" said Lan. "So they can't fall out?"

The grandmother picked up an old, clean bone and a sharp stone. She gave them to the girl.

The girl closed her eyes and walked along the shore in her head. Then she cut one little notch into the bone for every trap she had set. When she had finished, they counted the notches together, touching each one once. There were twelve.

"Can I ask one more thing?" said Lan. "What if the notches were in groups? One group for each place?"

So the girl cut them again on the other side of the bone, with a gap between each group. Three notches for the reeds. Four for the big rock. Five for the fig tree.

Every time a trap came in, she scratched a little line across one notch in its group.

At dusk, eleven notches had lines across them. One notch in the fig-tree group did not.

"It's at the fig tree," said the girl. "The last one is at the fig tree!"

They waded back to the fig tree in the last of the light. There, hidden under a root, was the twelfth trap. It was full of fish.

Every trap was in. Nobody would write down the girl's name, or her grandmother's.

Warm wind blew the day before away, and the grass under their feet was the Green.

On the side of the anvil, under the word DOOR, there was a new letter. A round O.

"A new word," said Inkling. "It's starting a new word."

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

Back on the Green

Lan drew a little line on the fridge list for every lost sock she found under the sofa. She found seven.

Tell the story back to someone. Why did the notches work when the pebbles did not? How did the groups help them find the last trap?