I want to talk about the Norfolk trip, and all the things that happened that day, but I'll first have to go back a bit, to give you the background and explain why it was we went.

Our first winter was just about over by then and we were all feeling much more settled. For all our little hiccups, Ruth and I had kept up our habit of rounding off the day in my room, talking over our hot drinks, and it was during one of those sessions, when we were larking around about something, that she suddenly said:

‘I suppose you've heard what Chrissie and Rodney have been saying.’

When I said I hadn't, she did a laugh and continued: ‘They're probably just having me on. Their idea of a joke. Forget I mentioned it.’

But I could see she wanted me to drag it out of her, so I kept pressing until in the end she said in a lowered voice:

‘You remember last week, when Chrissie and Rodney were away? They'd been up to this town called Cromer, up on the north Norfolk coast.’

‘What were they doing there?’

‘Oh, I think they've got a friend there, someone who used to live here. That's not the point. The point is, they claim they saw this … person. Working there in this open-plan office. And, well, you know. They reckon this person's a possible. For me.’

Though most of us had first come across the idea of ‘possibles’ back at Hailsham, we'd sensed we weren't supposed to discuss it, and so we hadn't - though for sure, it had both intrigued and disturbed us. And even at the Cottages, it wasn't a topic you could bring up casually. There was definitely more awkwardness around any talk of possibles than there was around, say, sex. At the same time, you could tell people were fascinated - obsessed, in some cases - and so it kept coming up, usually in solemn arguments, a world away from our ones about, say, James Joyce.

The basic idea behind the possibles theory was simple, and didn't provoke much dispute. It went something like this. Since each of us was copied at some point from a normal person, there must be, for each of us, somewhere out there, a model getting on with his or her life. This meant, at least in theory, you'd be able to find the person you were modelled from. That's why, when you were out there yourself - in the towns, shopping centres, transport cafés - you kept an eye out for ‘possibles’ - the people who might have been the models for you and your friends.

Beyond these basics, though, there wasn't much consensus. For a start, no one could agree what we were looking for when we looked for possibles. Some students thought you should be looking for a person twenty to thirty years older than yourself - the sort of age a normal parent would be. But others claimed this was sentimental. Why would there be a ‘natural’ generation between us and our models? They could have used babies, old people, what difference would it have made? Others argued back that they'd use for models people at the peak of their health, and that's why they were likely to be ‘normal parent’ age. But around here, we'd all sense we were near territory we didn't want to enter, and the arguments would fizzle out.

Then there were those questions about why we wanted to track down our models at all. One big idea behind finding your model was that when you did, you'd glimpse your future. Now I don't mean anyone really thought that if your model turned out to be, say, a guy working at a railway station, that's what you'd end up doing too. We all realised it wasn't that simple. Nevertheless, we all of us, to varying degrees, believed that when you saw the person you were copied from, you'd get some insight into who you were deep down, and maybe too, you'd see something of what your life held in store.

There were some who thought it stupid to be concerned about possibles at all. Our models were an irrelevance, a technical necessity for bringing us into the world, nothing more than that. It was up to each of us to make of our lives what we could. This was the camp Ruth always claimed to side with, and I probably did too. All the same, whenever we heard reports of a possible - whoever it was for - we couldn't help getting curious.

The way I remember it, sightings of possibles tended to come in batches. Weeks could go by with no one mentioning the subject, then one reported sighting would trigger off a whole spate of others. Most of them were obviously not worth pursuing: someone seen in a car going by, stuff like that. But every now and then, a sighting seemed to have substance to it - like the one Ruth told me about that night.

According to Ruth, Chrissie and Rodney had been busy exploring this seaside town they'd gone to and had split up for a while. When they'd met up again, Rodney was all excited and had told Chrissie how he'd been wandering the side-streets off the High Street, and had gone past an office with a large glass front. Inside had been a lot of people, some of them at their desks, some walking about and chatting. And that's where he'd spotted Ruth's possible.

‘Chrissie came and told me as soon as they got back. She made Rodney describe everything, and he did his best, but it was impossible to tell anything. Now they keep talking about driving me up there, but I don't know. I don't know if I ought to do anything about it.’

I can't remember exactly what I said to her that night, but I was at that point pretty sceptical. In fact, to be honest, my guess was that Chrissie and Rodney had made the whole thing up. I don't really want to suggest Chrissie and Rodney were bad people - that would be unfair. In many ways, I actually liked them. But the fact was, the way they regarded us newcomers, and Ruth in particular, was far from straightforward.

Chrissie was a tall girl who was quite beautiful when she stood up to her full height, but she didn't seem to realise this and spent her time crouching to be the same as the rest of us. That's why she often looked more like the Wicked Witch than a movie star - an impression reinforced by her irritating way of jabbing you with a finger the second before she said something to you. She always wore long skirts rather than jeans, and little glasses pressed too far into her face. She'd been one of the veterans who'd really welcomed us when we'd first arrived in the summer, and I'd at first been really taken by her and looked to her for guidance. But as the weeks had passed, I'd begun to have reservations. There was something odd about the way she was always mentioning the fact that we'd come from Hailsham, like that could explain almost anything to do with us. And she was always asking us questions about Hailsham - about little details, much like my donors do now - and although she tried to make out these were very casual, I could see there was a whole other dimension to her interest. Another thing that got to me was the way she always seemed to want to separate us: taking one of us aside when a few of us were doing something together, or else inviting two of us to join in something while leaving another two stranded - that sort of thing.

You'd hardly ever see Chrissie without her boyfriend, Rodney. He went around with his hair tied back in a ponytail, like a rock musician from the seventies, and talked a lot about things like reincarnation. I actually got to quite like him, but he was pretty much under Chrissie's influence. In any discussion, you knew he'd back up Chrissie's angle, and if Chrissie ever said anything mildly amusing, he'd be chortling and shaking his head like he couldn't believe how funny it was.

Okay, I'm maybe being a bit hard on these two. When I was remembering them with Tommy not so long ago, he thought they were pretty decent people. But I'm telling you all this now to explain why I was so sceptical about their reported sighting of Ruth's possible. As I say, my first instinct was not to believe it, and to suppose Chrissie was up to something.

The other thing that made me doubtful about all this had to do with the actual description given by Chrissie and Rodney: their picture of a woman working in a nice glass-fronted office. To me, at the time, this seemed just too close a match to what we then knew to be Ruth's ‘dream future’.

I suppose it was mainly us newcomers who talked about ‘dream futures’ that winter, though a number of veterans did too. Some older ones - especially those who'd started their training - would sigh quietly and leave the room when this sort of talk began, but for a long time we didn't even notice this happening. I'm not sure what was going on in our heads during those discussions. We probably knew they couldn't be serious, but then again, I'm sure we didn't regard them as fantasy either. Maybe once Hailsham was behind us, it was possible, just for that half year or so, before all the talk of becoming carers, before the driving lessons, all those other things, it was possible to forget for whole stretches of time who we really were; to forget what the guardians had told us; to forget Miss Lucy's outburst that rainy afternoon at the pavilion, as well as all those theories we'd developed amongst ourselves over the years. It couldn't last, of course, but like I say, just for those few months, we somehow managed to live in this cosy state of suspension in which we could ponder our lives without the usual boundaries. Looking back now, it feels like we spent ages in that steamed-up kitchen after breakfast, or huddled around half-dead fires in the small hours, lost in conversation about our plans for the future.

Mind you, none of us pushed it too far. I don't remember anyone saying they were going to be a movie star or anything like that. The talk was more likely to be about becoming a postman or working on a farm. Quite a few students wanted to be drivers of one sort or other, and often, when the conversation went this way, some veterans would begin comparing particular scenic routes they'd travelled, favourite roadside cafés, difficult roundabouts, that sort of thing. Today, of course, I'd be able to talk the lot of them under the table on those topics. Back then, though, I used to just listen, not saying a thing, drinking in their talk. Sometimes, if it was late, I'd close my eyes and nestle against the arm of a sofa - or of a boy, if it was during one of those brief phases I was officially ‘with’ someone - and drift in and out of sleep, letting images of the roads move through my head.

Anyway, to get back to my point, when this sort of talk was going on, it was often Ruth who took it further than anybody - especially when there were veterans around. She'd been talking about offices right from the start of the winter, but when it really took on life, when it became her ‘dream future’, was after that morning she and I walked into the village.

It was during a bitterly cold spell, and our boxy gas heaters had been giving us trouble. We'd spend ages trying to get them to light, clicking away with no result, and we'd had to give up on more and more - and along with them, the rooms they were supposed to heat. Keffers refused to deal with it, claiming it was our responsibility, but in the end, when things were getting really cold, he'd handed us an envelope with money and a note of some igniter fuel we had to buy. So Ruth and I had volunteered to walk to the village to get it, and that's why we were going down the lane that frosty morning. We'd reached a spot where the hedges were high on both sides, and the ground was covered in frozen cowpats, when Ruth suddenly stopped a few steps behind me.

It took me a moment to realise, so that by the time I turned back to her she was breathing over her fingers and looking down, engrossed by something beside her feet. I thought maybe it was some poor creature dead in the frost, but when I came up, I saw it was a colour magazine - not one of ‘Steve's magazines’, but one of those bright cheerful things that come free with newspapers. It had fallen open at this glossy double page advert, and though the paper had gone soggy and there was mud at one corner, you could see it well enough. It showed this beautifully modern open-plan office with three or four people who worked in it having some kind of joke with each other. The place looked sparkling and so did the people. Ruth was staring at this picture and, when she noticed me beside her, said: ‘Now that would be a proper place to work.’

Then she got self-conscious - maybe even cross that I'd caught her like that - and set off again much faster than before.

But a few evenings later, when several of us were sitting around a fire in the farmhouse, Ruth began telling us about the sort of office she'd ideally work in, and I immediately recognised it. She went into all the details - the plants, the gleaming equipment, the chairs with their swivels and castors - and it was so vivid everyone let her talk uninterrupted for ages. I was watching her closely, but it never seemed to occur to her I might make the connection - maybe she'd even forgotten herself where the image had come from. She even talked at one point about how the people in her office would all be ‘dynamic, go-ahead types’, and I remembered clearly those same words written in big letters across the top of the advert: ‘Are you the dynamic, go-ahead type?’ - something like that. Of course, I didn't say anything. In fact, listening to her, I even started wondering if maybe it was all feasible: if one day we might all of us move into a place like that and carry on our lives together.

Chrissie and Rodney were there that night, of course, hanging onto every word. And then for days afterwards, Chrissie kept trying to get Ruth to talk some more about it. I'd pass them sitting together in the corner of a room and Chrissie would be asking: ‘Are you sure you wouldn't put each other off, working all together in a place like that?’ just to get Ruth going on it again.

The point about Chrissie - and this applied to a lot of the veterans - was that for all her slightly patronising manner towards us when we'd first arrived, she was awestruck about our being from Hailsham. It took me a long time to realise this. Take the business about Ruth's office: Chrissie would never herself have talked about working in any office, never mind one like that. But because Ruth was from Hailsham, somehow the whole notion came within the realms of the possible. That's how Chrissie saw it, and I suppose Ruth did say a few things every now and then to encourage the idea that, sure enough, in some mysterious way, a separate set of rules applied to us Hailsham students. I never heard Ruth actually lie to veterans; it was more to do with not denying certain things, implying others. There were occasions when I could have brought the whole thing down over her head. But if Ruth was sometimes embarrassed, catching my eye in the middle of some story or other, she seemed confident I wouldn't give her away. And of course, I didn't.

So that was the background to Chrissie and Rodney's claim to have seen Ruth's ‘possible’, and you can maybe see now why I was wary about it. I wasn't keen on Ruth going with them to Norfolk, though I couldn't really say why. And once it became clear she was completely set on going, I told her I'd come too. At first, she didn't seem too delighted, and there was even a hint that she wouldn't let Tommy come with her either. In the end, though, we all went, the five of us: Chrissie, Rodney, Ruth, Tommy and me.