"Hello, Coraline," he said when she came in, without turning round.

"Mmph," said Coraline. "It's raining."

"Yup," said her father. "It's bucketing down."

"No," said Coraline, "it's just raining. Can I go outside?"

"What does your mother say?"

"She says, 'You're not going out in weather like that, Coraline Jones'."

"Then, no."

"But I want to carry on exploring."

"Then explore the flat," suggested her father. "Look-here's a piece of paper and a pen. Count all the doors and windows. List everything blue. Mount an expedition to discover the hot-water tank. And leave me alone to work."

"Can I go into the drawing room?" The drawing room was where the Joneses kept the expensive (and uncomfortable) furniture Coraline's grandmother had left them when she died. Coraline wasn't allowed in there. Nobody went in there. It was only for best.

"If you don't make a mess. And you don't touch anything."

Coraline considered this carefully, then she took the paper and pen and went off to explore the inside of the flat.

She discovered the hot-water tank (it was in a cupboard in the kitchen).

She counted everything blue (153).

She counted the windows (21).

She counted the doors (14).

Of the doors that she found, thirteen opened and closed. The other, the big, carved, brown wooden door at the far corner of the drawing room, was locked.

She said to her mother, "Where does that door go?"

"Nowhere, dear."

"It has to go somewhere."

Her mother shook her head. "Look," she told Coraline.

She reached up, and took a string of keys from the top of the kitchen doorframe. She sorted through them carefully and selected the oldest, biggest, blackest, rustiest key. They went into the drawing room. She unlocked the door with the key.