The bell in the lost-property box rang when nobody touched it.
Kato froze beside the cloakroom pegs. Rain tapped the windows like quick fingers.
He had come back for his maths book, and for one small secret. Tomorrow, he had to speak in assembly, and his stomach felt twisty.
The brass bell rang again. Clang!
Mr Finch, the caretaker, hurried in with his mop. "That bell has not rung for twenty years," he said.
Kato pointed to a damp string tied to its handle. The string disappeared through a hole in the wall.
When the quiet bell rings, follow the drip before the books learn to swim.
Kato swallowed. "Books cannot swim."
"No," said Mr Finch. "That is the worrying part."
⁂
They followed the string along the corridor. Drip. Drip. Drip.
It led down the narrow stairs to the basement, where the book-fair boxes waited for Monday. Water shone on the floor.
Kato’s shoes made tiny splashes. His hands squeezed into fists.
"The playground drain must be blocked," said Mr Finch. "Rainwater runs downhill, and this is the lowest room."
A cardboard castle stood near the boxes. Kato had made its drawbridge for assembly.
Water licked the castle’s wheels.
"We have to stop it," Kato said, before his fear could answer.
⁂
Outside, the playground was silver with rain. A brown river curled towards one black drain.
Leaves and a lost tennis ball plugged the metal grate.
Mr Finch pushed with his mop, but the ball would not move. Thunder cracked above the roof.
Kato spotted his umbrella by the door. Its handle was curved like a hook.
"I can reach it," he said.
He lay on his tummy, rain cold on his sleeves. He hooked the ball, pulled hard, and it popped free.
The drain gurgled like a giant drinking soup. Water spun down, carrying leaves away.
Far inside the school, the quiet bell gave one last tiny ping.
⁂
Mr Finch showed Kato the secret behind the wall. A cork float sat in a pipe, tied to the bell string.
"When water rose, the cork floated up and tugged the bell," he said.
Kato smiled. "So it was not magic."
"Only clever," said Mr Finch. "Clever can be just as exciting."
The next morning, Kato stood in assembly beside the rescued castle.
His knees wobbled, but he held up the brass bell.
"Yesterday," he said, "I followed a drip."
Everyone leaned closer. Kato took a deep breath and told the whole adventure.
