Ada had chosen the spot for their picnic: beside the duck pond, under the wide tree. She had even made a little paper ticket for the journey. But after lunch, rain stitched silver lines down the window. The path outside shone with puddles.

“We’ll keep our picnic indoors today,” Grandfather said. Ada sat on the rug with her chin in her hands. “I wanted the pond,” she said. The paper ticket lay beside her, with nowhere to go.

“Would you like some company, or a little quiet?” Grandfather asked. “Company,” said Ada. “But not a cheering-up song.” Grandfather sat down beside her. He did not sing. For a while, they watched a raindrop catch another raindrop on the glass.

Near Ada’s foot was her toy box. Inside waited a red wooden engine and two blue carriages. She lifted the engine out. Its wheels whispered across the rug. “This train could go somewhere,” she said at last. “Even if we can’t go to the pond.”

Grandfather unrolled a broad strip of drawing paper. Ada took a brown crayon and drew a line that wandered from one end to the other. “That is our route,” she decided. She drew a little curve on her ticket too. Now it belonged to this journey.

Grandfather put a folded blue cloth beside the line. “What might this be?” he asked. “A pond,” said Ada. “A very comfortable pond.” She found her wooden duck and placed it beside the blue water. The train had its first place to visit.

“Puddle Station!” Ada announced softly. The wooden duck was waiting, although it had forgotten its ticket. “Ducks can travel without one today,” she decided. She opened the space beside the last blue carriage so the duck could look at the train.

Grandfather made a small, surprised duck sound. Ada made a much bigger one. Then she stopped to listen. Real rain was still tapping the window. Their pretend pond did not replace the real pond outside. It was simply another place, here on the rug, with room for a very large duck voice.

An ochre cushion became a hill. Ada rolled the train towards it, then stopped. The paper line went straight ahead, but the hill was in the way. “We could move it,” Grandfather suggested. Ada considered the cushion. “Or the train could go round.”

She drew a wide bend beside the first line. “A detour,” Grandfather said. Ada tried the new word. The engine went round the hill, and the blue carriages followed. Nothing had to climb. At the far side, she looked back. Their route had become longer, and now it had a lovely bend.

They brought their picnic to the window: two cups, a little tray and bread on two plates. The train stopped beside the cushion hill. Outside, a bird shook rain from the garden tree. Inside, Ada drew another small curve on the edge of her ticket.

“I still wanted to go out,” she told Grandfather. “I know,” he said. “And I liked Puddle Station.” “I did too.” Both things fitted into the room. There was no need to squeeze one out. They ate slowly while the drops on the window joined together and slipped away.

Later, Ada changed into her yellow pyjamas. The drawing-paper journey could stay on the living-room rug until morning. She carried the engine and both carriages to the low shelf beside her bed. The train’s wheels made one last soft wooden sound.

“Where does it stop now?” Grandfather asked. “Goodnight Station,” said Ada. She parked the carriages behind the engine and laid the curved-line ticket beside them. The train did not need to keep travelling just because its route was not finished. There would be room for another station tomorrow.

Grandfather tucked the cream quilt around Ada. She could see the red engine from her pillow. The two blue carriages waited quietly, and beyond the closed window the rain had become a light patter. “Perhaps we can visit the real pond another day,” she murmured.

“Perhaps,” said Grandfather. “We’ll look at the weather together.” Ada thought of the paper line, the duck and the bend round the hill. She had not reached the place she had planned. She had travelled somewhere else with someone she loved. At Goodnight Station, the little train rested. So did Ada.