Noah was building a railway around the sofa when he heard a very polite whistle.
Pip-pip.
His small green train was standing at the end of the track.
"Are you ready?" Noah asked.
Pip-pip.
The train's lamp came on. The living room floor changed into a smooth railway beside the sea. Noah found himself in the driver's seat, wearing a blue cap that was exactly the right size.
The first station was called Pebble Bay. The second was called Shell Point. The third station had a sign that said HOME, with a moon painted beside it.
"We can get there before bedtime," Noah told the train.
They rolled past bright fishing boats and sleepy seagulls. Then a soft white fog came down over the tracks.
The train slowed.
Pip?
Noah looked ahead. The track was there, but it was hard to see where it turned.
"We should not rush," he said. "We can wait for the fog to lift."
But the fog did not lift. It sat on the sea like a big grey blanket.
From somewhere beyond the fog came a low, gentle sound.
Hooooo-ooo.
Noah leaned out of the window. A whale lifted her head from the water. She was big and blue-grey, with bright kind eyes.
"Hello, little train," she said. "I can hear your wheels thinking very hard."
"We are trying to get to Home Station," Noah explained. "But we cannot see the bend."
The whale nodded. "I know the sound of the rails. Listen with me."
She sang one long note. The sound travelled across the water, over the rocks and under the fog. Far ahead, a tiny answer came back: ting-ting, ting-ting.
"That is the signal at Home Station," said the whale. "Follow the sound, slowly."
Noah put both hands on the controls. The train moved at walking speed. Pip-pip. Then the whale sang again. Hooooo-ooo. The signal answered. Ting-ting.
At the first bend, Noah saw a line of silver fish jumping beside the track. At the second bend, he saw the station roof. At the third bend, the fog began to grow thin.
There was Home Station, with its moon sign glowing softly.
"We made it," Noah said.
Pip-pip-pip!
The whale lifted one fin. "You did not need to know everything at once," she said. "You only needed to travel safely, one bend at a time."
Noah waved back. The train rolled into the station and stopped beside a warm little platform.
Then Noah was back on the living room rug. His small green train was exactly where it had been. Outside, the evening was quiet.
Noah put the train beside his pillow for the night.
"Thank you for the song," he whispered.
Somewhere far away, or maybe very close, he thought he heard a whale singing one low, gentle note.