The other rats watched her from the corners of the room as she ran after it.

Now, rats can run faster than people, especially over short distances. But a large black rat holding a marble in its two front paws is no match for a determined girl (even if she is small for her age) moving at a run. Smaller black rats ran back and forth across her path, trying to distract her, but she ignored them all, keeping her eyes fixed on the one with the marble, who was heading straight out of the flat, towards the front door.

They reached the steps on the outside of the building.

Coraline had time to observe that the house itself was continuing to change, becoming less distinct, and flattening out, even as she raced down the stairs. It reminded her of a photograph of a house now, not the thing itself. Then she was simply racing pell-mell down the steps in pursuit of the rat, with no room in her mind for anything else, certain she was gaining on it. She was running fast-too fast, she discovered, as she came to the bottom of one flight of steps, and her foot skidded and twisted and she went crashing on to the concrete landing.

Her left knee was scraped and skinned, and the palm of one hand she had thrown out to stop herself was a mess of scraped skin and grit. It hurt a little, and it would, she knew, soon hurt much more. She picked the grit out of the palm and climbed to her feet and, as fast as she could, knowing that she had lost and it was already too late, she went down the final set of steps to ground level.

She looked around for the rat, but it was gone, and the marble with it.

Her hand stung where the skin had been scraped, and there was blood trickling down her ripped pyjama-leg from her knee. It was as bad as the summer that her mother had taken the training wheels off Coraline's bicycle; but then, back then, in with all the cuts and scrapes (her knees had had scabs on top of scabs) she had a feeling of achievement. She was learning something, doing something she had not known how to do before. Now she felt nothing but cold loss. She had failed the ghost-children. She had failed her parents. She had failed herself, failed everything.

She closed her eyes and wished that the earth would swallow her up.

There was a cough.

She opened her eyes, and saw the rat. It was lying on the brick path at the bottom of the steps, with a surprised look on its face-which was now several centimetres away from the rest of it. Its whiskers were stiff, its eyes were wide open, its teeth visible and yellow and sharp. A collar of wet blood glistened at its neck.

Beside the decapitated rat, a smug expression on its face, was the black cat. It rested one paw on the grey glass marble.

"I think I once mentioned," said the cat, "that I don't like rats at the best of times. It looked like you needed this one, however. I hope you don't mind my getting involved."

"I think," said Coraline, trying to catch her breath, "I think you may… have said… something of the sort."

The cat lifted its paw from the marble, which rolled towards Coraline. She picked it up. In her mind, a final voice whispered to her, urgently.

"She has lied to you. She will never give you up, now she has you. She will no more give any of us up than she can change her nature." The hairs on the back of Coraline's neck prickled, and Coraline knew that the girl's voice told the truth. She put the marble in her dressing-gown pocket with the others.

She had all three marbles, now.

All she needed to do was to find her parents.

And, Coraline realised, that was easy. She knew exactly where her parents were. If she had stopped to think, she might have known where they were all along. The other mother could not create. She could only transform, and twist, and change.

And the mantelpiece in the drawing room back home was quite empty. But, knowing that, she knew something else, as well.

"The other mother. She plans to break her promise. She won't let us go," said Coraline.

"I wouldn't put it past her," admitted the cat. "Like I said, there's no guarantee she'll play fair." And then he raised his head. "Hello… did you see that?"

"What?"

"Look behind you," said the cat.

The house had flattened out even more. It no longer looked like a photograph-more like a drawing, a crude, charcoal scribble of a house drawn on grey paper.

"Whatever's happening," said Coraline, "thank you for helping with the rat. I suppose I'm almost there, aren't I? So you go off into the mist or wherever you go, and I'll, well, I hope I get to see you at home. If she lets me go home."

The cat's fur was on end, and its tail was bristling like a chimney-sweep's brush. "What's wrong?" asked Coraline.

"They've gone," said the cat. "They aren't there any more. The ways in and out of this place. They just went flat."

"Is that bad?"

The cat lowered its tail, swishing it from side to side angrily. It made a low growling noise in the back of its throat. It walked in a circle, until it was facing away from Coraline, and then it began to walk backwards, stiffly, one step at a time, until it was pushing up against Coraline's leg. She put down a hand to stroke it, and could feel how hard its heart was beating. It was trembling, like a dead leaf in a storm.

"You'll be fine," said Coraline. "Everything's going to be fine. I'll take you home."

The cat said nothing.

"Come on, cat," said Coraline. She took a step back towards the steps, but the cat stayed where it was, looking miserable and, oddly, much smaller.

"If the only way out is past her," said Coraline, "then that's the way we're going to go." She went back to the cat, bent down and picked it up. The cat did not resist. It simply trembled. She supported its bottom with one hand and rested its front legs on her shoulder. The cat was heavy, but not too heavy to carry. It licked at the palm of her hand, where the blood from the scrape was welling up.

Coraline walked up the steps one at a time, heading back to her own flat. She was aware of the marbles clicking in her pocket, aware of the stone with the hole in it, aware of the cat pressing itself against her.

She got to her front door-now just a small-child's scrawl of a door-and she pushed her hand against it, half-expecting that her hand would rip through it, revealing nothing behind it but blackness and a scattering of stars.

But the door swung open, and Coraline went through.

Once inside, in her flat, or rather, in the flat that was not hers, Coraline was pleased to see that it had not transformed into the empty drawing that the rest of the house seemed to have become. It had depth and shadows, and someone who stood in the shadows waiting for Coraline to return.

"So you're back," said the other mother. She did not sound pleased. "And you brought vermin with you."

"No," said Coraline. "I brought a friend." She could feel the cat stiffening under her hands, as if it were anxious to be away. Coraline wanted to hold on to it like a teddy bear, for reassurance, but she knew that cats hate to be squeezed, and she suspected that frightened cats were liable to bite and scratch if provoked in any way, even if they were on your side.

"You know I love you," said the other mother, flatly.

"You have a very funny way of showing it," said Coraline. She walked down the hallway, then turned into the drawing room, steady step by steady step, pretending that she could not feel the other mother's blank black eyes on her back. Her grandmother's formal furniture was still there, and the painting on the wall of the strange fruit (but now the fruit in the painting had been eaten, and all that remained in the bowl was the browning core of an apple, several plum and peach stones, and the stem of what had formerly been a bunch of grapes). The lion-pawed table raked the carpet with its clawed wooden feet, as if it were impatient for something. At the end of the room, in the corner, stood the wooden door, which had once, in another place, opened on to a plain brick wall. Coraline tried not to stare at it. The window showed nothing but mist.