"I suppose there is," I said. Peter and Jamie, out there somewhere, specks of faces blurring into some vast moving throng. When I was twelve this was in some ways the worst possibility of all: that they had simply kept running that day, left me behind and never once looked back. I still have a reflexive habit of scanning for them in crowds-airports, gigs, train stations; it's faded a lot now, but when I was younger it would build to something like panic and I would end up whipping my head back and forth like a cartoon character, terrified that the one face I missed might be one of them. "I doubt it, though. There was a lot of blood."

Cassie was putting the shell in her pocket; she glanced up at me for a second. "I don't know the details."

"I'll leave you the file," I said. Annoyingly, it took an effort to say it, as if I were handing over my diary or something. "See what you think."

The tide was starting to come in. Sandymount beach slopes so gradually that at low tide the sea is almost invisible, a tiny gray edge far off on the horizon; it swoops in dizzyingly fast, from all directions at once, and sometimes people get stranded. In a few minutes it would be up to our feet. "We'd better head back," Cassie said. "Sam's coming over for dinner, remember?"

"Oh, that's right," I said, without much enthusiasm. I do like Sam-everyone likes Sam, except Cooper-but I wasn't sure I was in the mood for other people. "Why did you invite him?"

"The case?" she said sweetly. "Work? Dead person?" I made a face at her; she grinned back.

The two sticky toddlers in the stroller were whacking at each other with luridly colored toys. "Britney! Justin!" the mother screamed over their yells. "Shurrup or I'll kill the fucking pair of yous!" I got an arm around Cassie's neck and managed to pull her a safe distance away before we both burst out laughing.

I did eventually settle in to boarding school, by the way. When my parents dropped me off for the beginning of second year (me weeping, begging, clutching the car door handle as the disgusted housemaster plucked me up by the waist and prized my fingers away one by one) I recognized that, no matter what I did or how I pleaded, they were never going to let me come home. After that I stopped being homesick.

I had very little choice. My unrelenting misery in first year had worn me almost to breaking point (I had grown used to flashes of dizziness every time I stood up, moments when I couldn't remember a classmate's name or the way to the dining hall), and even thirteen-year-old resilience has its limits; a few more months of that and I would probably have ended up having some kind of embarrassing nervous breakdown. But when it comes to the crunch I have, as I say, excellent survival instincts. That first night of second year I sobbed myself to sleep, and then I woke up the next morning and decided that I would never be homesick again.

After that I found it, to my slight surprise, quite easy to settle in. Without really paying attention, I had picked up much of the bizarre, inbred school slang ("scrots" for juniors, "mackos" for teachers), and my accent went from County Dublin to Home Counties within a week. I made friends with Charlie, who sat next to me in geography and had a round solemn face and an irresistible chuckle; when we got old enough, we shared a study and experimental joints that his brother at Cambridge gave him and long, confused, yearning conversations about girls. My academic work was mediocre at best-I had bent myself so fiercely to the idea of school as an eternal, inescapable fate that I had trouble imagining anything beyond it, so it was hard to remember why I was supposed to be studying-but I turned out to be a pretty good swimmer, good enough for the school team, which got me a lot more respect from both masters and boys than good exam results would have. In fifth year they even made me a prefect; I tend to attribute this, like my Murder appointment, to the fact that I looked the part.

I spent a lot of the holidays at Charlie's home in Herefordshire, learning to drive on his dad's old Mercedes (jolting country roads, the windows wide open, Bon Jovi blaring on the car stereo and both of us singing along out of tune at the top of our lungs) and falling in love with his sisters. I found I no longer particularly wanted to go home. The house in Leixlip was flimsy and dark and smelled of damp, and my mother had arranged my stuff all wrong in my new bedroom; it felt awkward and temporary, like hurriedly assembled refugee accommodation, not like a home. All the other kids on the street had dangerous-looking haircuts and made unintelligible fun of my accent.

My parents had noticed the change in me, but rather than being pleased that I had settled in at school, as you'd expect, they seemed taken aback, nervous of the unfamiliar, self-contained person I was becoming. My mother tiptoed around the house and asked me timidly what I would like for my tea; my father tried to start man-to-man chats that always ran aground, after much throat-clearing and newspaper-rattling, on my vacant, passive silence. I understood, rationally, that they had sent me to boarding school to protect me from the unrelenting waves of journalists and futile police interviews and curious classmates, and I was aware that this had probably been an excellent decision; but some part of me believed, unassailably and wordlessly and perhaps with a fleck of justice, that they had sent me away because they were afraid of me. Like some monstrously deformed child who should never have lived beyond infancy, or a conjoined twin whose other half died under the knife, I had-simply by surviving-become a freak of nature.

8

Sam arrived bang on time, looking like a kid on a first date-he had even slicked down his fair hair, ineffectually, with a cowlick at the back-and carrying a bottle of wine. "There you go," he said, presenting it to Cassie. "I didn't know what you were cooking, but the guy in the shop said this will go with just about anything."

"That's perfect," Cassie told him, turning down the music (Ricky Martin, in Spanish; she has this boppy mix that she turns up loud when she's cooking or doing housework) and heading for the wardrobe to find wineglass equivalents. "I'm only making pasta anyway. Corkscrew's in that drawer. Rob, sweetie, you have to actually stir the sauce, not just hold the spoon in the pan."

"Listen, Martha Stewart, am I doing this or are you?"

"Neither, apparently. Sam, are you having wine or are you driving?"

"Maddox, it's tinned tomatoes and basil, it's hardly haute cuisine-"

"Did they surgically remove your palate at birth, or did you have to cultivate such an utter lack of refinement? Sam, wine?"

Sam looked a little bemused. Sometimes Cassie and I forget that we can have that effect on people, especially when we're off duty and in a good mood, which we were. I know this sounds odd, given what we had been doing all day, but in the squads with a high horror quota-Murder, Sex Crime, Domestic Violence-either you learn to switch off or you transfer to Art and Antiques. If you let yourself think too much about the victims (what went through their minds in their last seconds, all the things they'll never do, their devastated families), you end up with an unsolved case and a nervous breakdown. I was, obviously, having a harder time than usual switching off; but it was doing me good, the comforting routine of making dinner and annoying Cassie.

"Um, yes, please," Sam said. He looked around awkwardly for somewhere to put his coat; Cassie took it and tossed it on the futon. "My uncle has a house in Ballsbridge-yeah, yeah, I know," he said, as we both gave him mock-impressed looks, "and I still have a key. I sometimes stay the night if I'm after having a few pints." He looked from one to the other of us, waiting for us to comment.