Sam didn't sell his house, either. Instead, I heard, he rented it out at a nominal rate to a young widow whose husband had died of a brain aneurysm, leaving her with a toddler, a difficult pregnancy and no life insurance. As she was a freelance cellist, she couldn't even collect unemployment benefit; she had fallen behind on her rent, her landlord had evicted her, and she and the children had been living in a B amp;B provided by a charity organization. I have no idea how Sam found this woman-I'd have thought you would need to go to Victorian London for that level of picturesque, deserving pathos; he had presumably put in a characteristic amount of research. He had moved to a rental flat in Blanchardstown, I think, or some equivalent suburban hell. The main theories were that he was about to leave the force for the priesthood, and that he had a terminal disease.

Sophie and I went out once or twice-I did, after all, owe her dinner and cocktails several times over. I thought we had a good time, and she didn't ask any difficult questions, which I took as a good sign. After a few dates, though, and before the relationship had really progressed enough to merit the name, she dumped me. She informed me, matter-of-factly, that she was old enough to know the difference between intriguing and fucked up. "You should go for younger women," she advised me. "They can't always tell."

Inevitably, sometime during those interminable months in my apartment (hand after hand of late-night solitaire poker, near-lethal quantities of Radiohead and Leonard Cohen), my thoughts turned back to Knocknaree. I had, of course, sworn never to let the place cross my mind again; but human beings can't help being curious, I suppose, as long as the knowledge doesn't come at too high a price.

Imagine my surprise, then, when I realized that there was nothing there. Everything before my first day of boarding school had apparently been excised from my mind, with surgical precision and this time for good. Peter, Jamie, the bikers and Sandra, the wood, every scrap of memory I had retrieved with such laborious care over the course of Operation Vestal: gone. I could remember what it had been like to remember these scenes, once upon a time, but now they had the remote, secondhand quality of old films I had watched or stories I had been told, I saw them as if from a vast distance-three brown-skinned kids in battered shorts, spitting on Willy Little's head from the branches and scrambling away, giggling-and I knew with cold certainty that over time even these deracinated images would shrivel up to nothing and blow away. They no longer seemed to belong to me, and I couldn't shake the dark, implacable sense that this was because I had forfeited my right to them, once and for all.

Only one image remained. A summer afternoon, Peter and me sprawled on the grass in his front garden. We had been trying, in a halfhearted kind of way, to make a periscope from instructions in an old comic book, but we were supposed to have a cardboard tube out of a roll of paper towel, and we couldn't ask our mothers for one because we weren't talking to them. We had used rolled-up newspaper instead, but it kept buckling, so all we could see through the periscope was the sports page, backwards.

We were both in a really bad mood. It was the first week of the holidays and it was sunny, so it should have been a brilliant day, we should have been fixing the tree house or freezing our mickeys off swimming in the river or something; but on our way home from the last day of school on Friday, Jamie had said, to her shoes, "Three months and I go to boarding school."

"Shut up," Peter had said, shoving her, not hard. "No you won't. She'll give in." But it had taken all the shine off the holidays, like a huge black smoke-cloud hanging over everything in sight. We couldn't go inside because our parents were all mad at us for not talking, and we couldn't go into the wood or do anything good because everything we thought of felt stupid, and we couldn't even go find Jamie and get her to come out because she would just shake her head and say "What's the point?" and make everything even worse. So we were lying in the garden, bored and itchy and annoyed with each other and with the periscope for not working and with the entire world for being a pain in the hole. Peter was pulling up blades of grass, biting the ends off and spitting them up into the air, in a restless automatic rhythm. I was lying on my stomach, one eye open to stare down at the ants bustling back and forth, and the sun was making my hair sweat. This summer doesn't even count, I thought. This summer sucks.

Jamie's door slammed open and she shot out like she had been fired from a cannon, her mother calling after her with a rueful smile in her voice and the door ricocheting shut with a bang and the Carmichaels' horrible Jack Russell exploding into high-pitched inbred hysteria. Peter and I sat up. Jamie skidded to a halt at her gate, head whipping round to look for us, and when we shouted to her she raced down the path, leaped over Peter's garden wall and tumbled flat on the grass with an arm hooked round each of our necks, bringing us down with her. We were all yelling at the same time and it took a few seconds before I figured out what Jamie was shouting: "I'm staying! I'm staying! I don't have to go!"

The summer came to life. It burst from gray to fierce blue and gold in the blink of an eye; the air pealed with grasshoppers and lawnmowers, swirled with branches and bees and dandelion seeds, it was soft and sweet as whipped cream, and over the wall the wood was calling us in the loudest of silent voices, it was shaking out all its best treasures to welcome us home. Summer tossed out a fountain of ivy tendrils, caught us straight under the breastbones and tugged; summer, redeemed and unfurling in front of us, a million years long.

We disentangled ourselves and sat up panting, barely able to believe it.

"Seriously?" I said. "For definite?"

"Yeah. She said, 'We'll see, I'll have another think about it and we'll sort something out,' but that always means it's OK but she just doesn't want to say so yet. I'm going nowhere!"

Jamie ran out of words, so she pushed me over. I grabbed her arm, got on top of her and gave her a Chinese burn. There was a huge grin straight across my face, and I was so happy that I thought it would never come off again.

Peter was on his feet. "We have to celebrate. Picnic in the castle. Go home and get stuff and meet there."

Rocketing through the house to the kitchen, my mother hoovering somewhere upstairs-"Mam! Jamie's staying, can I take stuff for a picnic?" as I grabbed three packets of crisps and a half-package of custard creams and shoved them up my T-shirt-then out the door again, waving to my mother's startled face on the landing, and one-handed over the wall.

Coke cans fizzing and foaming over, and us on our feet on top of the castle wall to clank them together. "We won!" Peter shouted up into the branches and the glittering bands of light, head thrown back and fist punching the air. "We did it!"

Jamie screamed, "I'm gonna stay here forever!" and danced on the wall like a thing made of air, "Forever and ever and ever!" And I just yelled, wild wordless whoops, and the wood caught our voices and tossed them outwards in great expanding ripples, wove them into the whirlpool of leaves and the jink and bubble of the river and the rustling calling web of rabbits and beetles and robins and all the other denizens of our domain, into one long high paean.

This memory, alone of all my hoard, did not dissolve into smoke and slide away through my fingers. It remained-still remains-sharp-edged and warm and mine, a single bright coin left in my hand. I suppose that, if the wood was going to leave me only one moment, that was a kind one to choose.