But the older he got, the more Will began to wonder. Why were there no pictures of his father in this part of the world or that, riding with frost-bearded men on Arctic sledges or examining creeper-covered ruins in the jungle? Had nothing survived of the trophies and curiosities he must have brought home? Was nothing written about him in a book?

His mother didn't know. But one thing she had said stuck in his mind.

She said, "One day, you'll follow in your father's footsteps. You're going to be a great man too. You'll take up his mantle."

And though Will didn't know what that meant, he understood the sense of it, and felt uplifted with pride and purpose. All his games were going to come true. His father was alive, lost somewhere in the wild, and he was going to rescue him and take up his mantle… It was worth living a difficult life, if you had a great aim like that.

So he kept his mother's trouble secret. There were times when she was calmer and clearer than others, and he took care to learn from her then how to shop and cook and keep the house clean, so that he could do it when she was confused and frightened. And he learned how to conceal himself, too, how to remain unnoticed at school, how not to attract attention from the neighbors, even when his mother was in such a state of fear and madness that she could barely speak. What Will himself feared more than anything was that the authorities would find out about her, and take her away, and put him in a home among strangers. Any difficulty was better than that. Because there came times when the darkness cleared from her mind, and she was happy again, and she laughed at her fears and blessed him for looking after her so well; and she was so full of love and sweetness then that he could think of no better companion, and wanted nothing more than to live with her alone forever.

But then the men came.

They weren't police, and they weren't social services, and they weren't criminals—at least as far as Will could judge. They wouldn't tell him what they wanted, in spite of his efforts to keep them away; they'd speak only to his mother. And her state was fragile just then.

But he listened outside the door, and heard them ask about his father, and felt his breath come more quickly.

The men wanted to know where John Parry had gone, and whether he'd sent anything back to her, and when she'd last heard from him, and whether he'd had contact with any foreign embassies. Will heard his mother getting more and more distressed, and finally he ran into the room and told them to go.

He looked so fierce that neither of the men laughed, though he was so young. They could easily have knocked him down, or held him off the floor with one hand, but he was fearless, and his anger was hot and deadly.

So they left. Naturally, this episode strengthened Will's conviction: his father was in trouble somewhere, and only he could help. His games weren't childish anymore, and he didn't play so openly. It was coming true, and he had to be worthy of it.

And not long afterward the men came back, insisting that Will's mother had something to tell them. They came when Will was at school, and one of them kept her talking downstairs while the other searched the bedrooms. She didn't realize what they were doing. But Will came home early and found them, and once again he blazed at them, and once again they left.

They seemed to know that he wouldn't go to the police, for fear of losing his mother to the authorities, and they got more and more persistent. Finally they broke into the house when Will had gone to fetch his mother home from the park. It was getting worse for her now, and she believed that she had to touch every separate slat in every separate bench beside the pond. Will would help her, to get it done quicker. When they got home that day they saw the back of the men's car disappearing out of the close, and he got inside to find that they'd been through the house and searched most of the drawers and cupboards.

He knew what they were after. The green leather case was his mother's most precious possession; he would never dream of looking through it, and he didn't even know where she kept it. But he knew it contained letters, and he knew she read them sometimes, and cried, and it was then that she talked about his father. So Will supposed that this was what the men were after, and knew he had to do something about it.

He decided first to find somewhere safe for his mother to stay. He thought and thought, but he had no friends to ask, and the neighbors were already suspicious, and the only person he thought he could trust was Mrs. Cooper. Once his mother was safely there, he was going to find the green leather case and look at what was in it, and then he was going to go to Oxford, where he'd find the answer to some of his questions. But the men came too soon.

And now he'd killed one of them.

So the police would be after him too.

Well, he was good at not being noticed. He'd have to not be noticed harder than he'd ever done in his life before, and keep it up as long as he could, till either he found his father or they found him. And if they found him first, he didn't care how many more of them he killed.

Later that day, toward midnight in fact, Will was walking out of the city of Oxford, forty miles away. He was tired to his very bones. He had hitchhiked, and ridden on two buses, and walked, and reached Oxford at six in the evening, too late to do what he needed to do. He'd eaten at a Burger King and gone to a cinema to hide (though what the film was, he forgot even as he was watching it), and now he was walking along an endless road through the suburbs, heading north.

No one had noticed him so far. But he was aware that he'd better find somewhere to sleep before long, because the later it got, the more noticeable he'd be. The trouble was that there was nowhere to hide in the gardens of the comfortable houses along this road, and there was still no sign of open country.

He came to a large traffic circle where the road going north crossed the Oxford ring road going east and west. At this time of night there was very little traffic, and the road where he stood was quiet, with comfortable houses set back behind a wide expanse of grass on either side. Planted along the grass at the road's edge were two lines of hornbeam trees, odd-looking things with perfectly symmetrical close-leafed crowns, more like children's drawings than like real trees. The streetlights made the scene look artificial, like a stage set. Will was stupefied with exhaustion, and he might have gone on to the north, or he might have laid his head on the grass under one of those trees and slept; but as he stood trying to clear his head, he saw a cat.

She was a tabby, like Moxie. She padded out of a garden on the Oxford side of the road, where Will was standing. Will put down his tote bag and held out his hand, and the cat came up to rub her head against his knuckles, just as Moxie did. Of course, every cat behaved like that, but all the same Will felt such a longing for home that tears scalded his eyes.

Eventually the cat turned away. This was night, and there was a territory to patrol, there were mice to hunt. She padded across the road and toward the bushes just beyond the hornbeam trees, and there she stopped.

Will, still watching, saw the cat behave curiously.

She reached out a paw to pat something in the air in front of her, something quite invisible to Will. Then she leaped backward, back arched and fur on end, tail held out stiffly. Will knew cat behavior. He watched more alertly as the cat approached the spot again, just an empty patch of grass between the hornbeams and the bushes of a garden hedge, and patted the air once more.

Again she leaped back, but less far and with less alarm this time. After another few seconds of sniffing, touching, and whisker twitching, curiosity overcame wariness.