When I got outside, it was obvious the excitement from when we'd first arrived had evaporated completely. We walked in silence, Rodney leading the way, through little backstreets hardly penetrated by the sun, the pavements so narrow we often had to shuffle along in single file. It was a relief to come out onto the High Street where the noise made our rotten mood less obvious. As we crossed at a pelican to the sunnier side, I could see Rodney and Chrissie conferring about something and I wondered how much of the bad atmosphere had to do with their believing we were holding back on some big Hailsham secret, and how much was just to do with Ruth's having a go at Tommy.

Then once we'd crossed the High Street, Chrissie announced she and Rodney wanted to go shopping for birthday cards. Ruth was stunned by this, but Chrissie just went on:

‘We like buying them in big batches. It's always cheaper in the long run. And you've always got one handy when it's someone's birthday.’ She pointed to the entrance of a Woolworth's shop. ‘You can get pretty good cards in there really cheap.’

Rodney was nodding, and I thought there was something a little bit mocking around the edges of his smile. ‘Of course,’ he said, ‘you end up with a lot of cards the same, but you can put your own illustrations on them. You know, personalise them.’

Both veterans were now standing in the middle of the pavement, letting people with pushchairs move round them, waiting for us to put up a challenge. I could tell Ruth was furious, but without Rodney's co-operation there wasn't much that could be done anyway.

So we went into the Woolworth's, and immediately I felt much more cheerful. Even now, I like places like that: a large store with lots of aisles displaying bright plastic toys, greeting cards, loads of cosmetics, maybe even a photo booth. Today, if I'm in a town and find myself with some time to kill, I'll stroll into somewhere just like that, where you can hang around and enjoy yourself, not buying a thing, and the assistants don't mind at all.

Anyway, we went in and before long we'd wandered apart to look at different aisles. Rodney had stayed near the entrance beside a big rack of cards, and further inside, I spotted Tommy under a big pop-group poster, rummaging through the music cassettes. After about ten minutes, when I was somewhere near the back of the store, I thought I heard Ruth's voice and wandered towards it. I'd already turned into the aisle - one with fluffy animals and big boxed jigsaws - before I realised Ruth and Chrissie were standing together at the end of it, having some sort of tête-à-tête. I wasn't sure what to do: I didn't want to interrupt, but it was time we were leaving and I didn't want to turn and walk off again. So I just stopped where I was, pretended to examine a jigsaw and waited for them to notice me.

That was when I realised they were back on the subject of this rumour. Chrissie was saying, in a lowered voice, something like:

‘But all that time you were there, I'm amazed you didn't think more about how you'd do it. About who you'd go to, all of that.’

‘You don't understand,’ Ruth was saying. ‘If you were from Hailsham, then you'd see. It's never been such a big deal for us. I suppose we've always known if we ever wanted to look into it, all we'd have to do is get word back to Hailsham …’

Ruth saw me and broke off. When I lowered the jigsaw and turned to them, they were both looking at me angrily. At the same time, it was like I'd caught them doing something they shouldn't, and they moved apart self-consciously.

‘It's time we were off,’ I said, pretending to have heard nothing.

But Ruth wasn't fooled. As they came past, she gave me a really dirty look.

So by the time we set off again, following Rodney in search of the office where he'd seen Ruth's possible the month before, the atmosphere between us was worse than ever. Things weren't helped either by Rodney repeatedly taking us down the wrong streets. At least four times, he led us confidently down a turning off the High Street, only for the shops and offices to run out, and we'd have to turn and come back. Before long, Rodney was looking defensive and on the verge of giving up. But then we found it.

Again, we'd turned and were heading back towards the High Street, when Rodney had stopped suddenly. Then he'd indicated silently an office on the other side of the street.

There it was, sure enough. It wasn't exactly like the magazine advert we'd found on the ground that day, but then it wasn't so far off either. There was a big glass front at street-level, so anyone going by could see right into it: a large open-plan room with maybe a dozen desks arranged in irregular L-patterns. There were the potted palms, the shiny machines and swooping desk lamps. People were moving about between desks, or leaning on a partition, chatting and sharing jokes, while others had pulled their swivel chairs close to each other and were enjoying a coffee and sandwich.

‘Look,’ Tommy said. ‘It's their lunch break, but they don't go out. Don't blame them either.’

We kept on staring, and it looked like a smart, cosy, self-contained world. I glanced at Ruth and noticed her eyes moving anxiously around the faces behind the glass.

‘Okay, Rod,’ Chrissie said. ‘So which one's the possible?’

She said this almost sarcastically, like she was sure the whole thing would turn out to be a big mistake on his part. But Rodney said quietly, with a tremor of excitement:

‘There. Over in that corner. In the blue outfit. Her, talking now to the big red woman.’

It wasn't obvious, but the longer we kept looking, the more it seemed he had something. The woman was around fifty, and had kept her figure pretty well. Her hair was darker than Ruth's - though it could have been dyed - and she had it tied back in a simple pony-tail the way Ruth usually did. She was laughing at something her friend in the red outfit was saying, and her face, especially when she was finishing her laugh with a shake of her head, had more than a hint of Ruth about it.

We all kept on watching her, not saying a word. Then we became aware that in another part of the office, a couple of the other women had noticed us. One raised a hand and gave us an uncertain wave. This broke the spell and we took to our heels in giggly panic.

We stopped again further down the street, talking excitedly all at once. Except for Ruth, that is, who remained silent in the middle of it. It was hard to read her face at that moment: she certainly wasn't disappointed, but then she wasn't elated either. She had on a half-smile, the sort a mother might have in an ordinary family, weighing things up while the children jumped and screamed around her asking her to say, yes, they could do whatever. So there we were, all coming out with our views, and I was glad I could say honestly, along with the others, that the woman we'd seen was by no means out of the question. The truth was, we were all relieved: without quite realising it, we'd been bracing ourselves for a let-down. But now we could go back to the Cottages, Ruth could take encouragement from what she'd seen, and the rest of us could back her up. And the office life the woman appeared to be leading was about as close as you could hope to the one Ruth had often described for herself. Regardless of what had been going on between us that day, deep down, none of us wanted Ruth to return home despondent, and at that moment we thought we were safe. And so we would have been, I'm pretty sure, had we put an end to the matter at that point.

But then Ruth said: ‘Let's sit over there, over on that wall. Just for a few minutes. Once they've forgotten about us, we can go and have another look.’

We agreed to this, but as we walked towards the low wall around the small car park Ruth had indicated, Chrissie said, perhaps a little too eagerly:

‘But even if we don't get to see her again, we're all agreed she's a possible. And it's a lovely office. It really is.’

‘Let's just wait a few minutes,’ Ruth said. ‘Then we'll go back.’

I didn't sit on the wall myself because it was damp and crumbling, and because I thought someone might appear any minute and shout at us for sitting there. But Ruth did sit on it, knees on either side like she was astride a horse. And today I have these vivid images of the ten, fifteen minutes we waited there. No one's talking about the possible any more. We're pretending instead that we're just killing a bit of time, maybe at a scenic spot during a carefree day-trip. Rodney's doing a little dance to demonstrate what a good feeling there is. He gets up on the wall, balances along it then deliberately falls off. Tommy's making jokes about some passers-by, and though they're not very funny, we're all laughing. Just Ruth, in the middle, astride the wall, remains silent. She keeps the smile on her face, but hardly moves. There's a breeze messing up her hair, and the bright winter sun's making her crinkle up her eyes, so you're not sure if she's smiling at our antics, or just grimacing in the light. These are the pictures I've kept of those moments we waited by that car park. I suppose we were waiting for Ruth to decide when it was time to go back for a second look. Well, she never got to make that decision because of what happened next.

Tommy, who had been mucking about on the wall with Rodney, suddenly jumped down and went still. Then he said: ‘That's her. That's the same one.’

We all stopped what we were doing and watched the figure coming from the direction of the office. She was now wearing a cream-coloured overcoat, and struggling to fasten her briefcase as she walked. The buckle was giving her trouble, so she kept slowing down and starting again. We went on watching her in a kind of trance as she went past on the other side. Then as she was turning into the High Street, Ruth leapt up and said: ‘Let's see where she goes.’

We came out of our trance and were off after her. In fact, Chrissie had to remind us to slow down or someone would think we were a gang of muggers going after the woman. We followed along the High Street at a reasonable distance, giggling, dodging past people, separating and coming together again. It must have been around two o'clock by then, and the pavement was busy with shoppers. At times we nearly lost sight of her, but we kept up, loitering in front of window displays when she went into a shop, squeezing past pushchairs and old people when she came out again.

Then the woman turned off the High Street into the little lanes near the seafront. Chrissie was worried she'd notice us away from the crowds, but Ruth just kept going, and we followed behind her.

Eventually we came into a narrow side-street that had the occasional shop, but was mainly just ordinary houses. We had to walk again in single file, and once when a van came the other way, we had to press ourselves into the houses to let it pass. Before long there was only the woman and us in the entire street, and if she'd glanced back, there was no way she wouldn't have noticed us. But she just kept walking, a dozen or so steps ahead, then went in through a door - into ‘The Portway Studios’.

I've been back to the Portway Studios a number of times since then. It changed owners a few years ago and now sells all kinds of arty things: pots, plates, clay animals. Back then, it was two big white rooms just with paintings - beautifully displayed with plenty of spaces between them. The wooden sign hanging over the door is still the same one though. Anyway, we decided to go in after Rodney pointed out how suspicious we looked in that quiet little street. Inside the shop, we could at least pretend we were looking at the pictures.

We came in to find the woman we'd been following talking to a much older woman with silver hair, who seemed to be in charge of the place. They were sitting on either side of a small desk near the door, and apart from them, the gallery was empty. Neither woman paid much attention as we filed past, spread out and tried to look fascinated by the pictures.

Actually, preoccupied though I was with Ruth's possible, I did begin to enjoy the paintings and the sheer peacefulness of the place. It felt like we'd come a hundred miles from the High Street. The walls and ceilings were peppermint, and here and there, you'd see a bit of fishing net, or a rotted piece from a boat stuck up high near the cornicing. The paintings too - mostly oils in deep blues and greens - had sea themes. Maybe it was the tiredness suddenly catching up with us - after all, we'd been travelling since before dawn - but I wasn't the only one who went off into a bit of a dream in there. We'd all wandered into different corners, and were staring at one picture after another, only occasionally making the odd hushed remark like: ‘Come and look at this!’ All the time, we could hear Ruth's possible and the silver-haired lady talking on and on. They weren't especially loud, but in that place, their voices seemed to fill the entire space. They were discussing some man they both knew, how he didn't have a clue with his children. And as we kept listening to them, stealing the odd glance in their direction, bit by bit, something started to change. It did for me, and I could tell it was happening for the others. If we'd left it at seeing the woman through the glass of her office, even if we'd followed her through the town then lost her, we could still have gone back to the Cottages excited and triumphant. But now, in that gallery, the woman was too close, much closer than we'd ever really wanted. And the more we heard her and looked at her, the less she seemed like Ruth. It was a feeling that grew among us almost tangibly, and I could tell that Ruth, absorbed in a picture on the other side of the room, was feeling it as much as anyone. That was probably why we went on shuffling around that gallery for so long; we were delaying the moment when we'd have to confer.

Then suddenly the woman had left, and we all kept standing about, avoiding each other's eyes. But none of us had thought to follow the woman, and as the seconds kept ticking on, it became like we were agreeing, without speaking, about how we now saw the situation.

Eventually the silver-haired lady came out from behind her desk and said to Tommy, who was the nearest to her: ‘That's a particularly lovely work. That one's a favourite of mine.’

Tommy turned to her and let out a laugh. Then as I was hurrying over to help him out, the lady asked: ‘Are you art students?’

‘Not exactly,’ I said before Tommy could respond. ‘We're just, well, keen.’

The silver-haired lady beamed, then started to tell us how the artist whose work we were looking at was related to her, and all about the artist's career thus far. This had the effect, at least, of breaking the trance-like state we'd been in, and we gathered round her to listen, the way we might have done at Hailsham when a guardian started to speak. This really got the silver-haired lady going, and we kept nodding and exclaiming while she talked about where the paintings had been done, the times of day the artist liked to work, how some had been done without sketches. Then there came a kind of natural end to her lecture, and we all gave a sigh, thanked her and went out.

The street outside being so narrow, we couldn't talk properly for a while longer, and I think we were all grateful for that. As we walked away from the gallery in single file, I could see Rodney, up at the front, theatrically stretching out his arms, like he was exhilarated the way he'd been when we'd first arrived in the town. But it wasn't convincing, and once we came out onto a wider street, we all shuffled to a halt.

We were once again near a cliff edge. And like before, if you peered over the rail, you could see the paths zigzagging down to the seafront, except this time you could see the promenade at the bottom with rows of boarded-up stalls.

We spent a few moments just looking out, letting the wind hit us. Rodney was still trying to be cheerful, like he'd decided not to let any of this business spoil a good outing. He was pointing out to Chrissie something in the sea, way off on the horizon. But Chrissie turned away from him and said:

‘Well, I think we're agreed, aren't we? That isn't Ruth.’ She gave a small laugh and laid a hand on Ruth's shoulder. ‘I'm sorry. We're all sorry. But we can't blame Rodney really. It wasn't that wild a try. You've got to admit, when we saw her through those windows, it did look …’ She trailed off, then touched Ruth on the shoulder again.

Ruth said nothing, but gave a little shrug, almost as if to shrug off the touch. She was squinting into the distance, at the sky rather than the water. I could tell she was upset, but someone who didn't know her well might well have supposed she was being thoughtful.

‘Sorry, Ruth,’ Rodney said, and he too gave Ruth a pat on the shoulder. But he had a smile on his face like he didn't expect for one moment to be blamed for anything. It was the way someone apologised when they'd tried to do you a favour, but it hadn't worked out.

Watching Chrissie and Rodney at that moment, I remember thinking, yes, they were okay. They were kind in their way and were trying to cheer Ruth up. At the same time, though, I remember feeling - even though they were the ones doing the talking, and Tommy and I were silent - a sort of resentment towards them on Ruth's behalf. Because however sympathetic they were, I could see that deep down they were relieved. They were relieved things had turned out the way they had; that they were in a position to comfort Ruth, instead of being left behind in the wake of a dizzying boost to her hopes. They were relieved they wouldn't have to face, more starkly than ever, the notion which fascinated and nagged and scared them: this notion of theirs that there were all kinds of possibilities open to us Hailsham students that weren't open to them. I remember thinking then how different they actually were, Chrissie and Rodney, from the three of us.

Then Tommy said: ‘I don't see what difference it makes. It was just a bit of fun we were having.’

‘A bit of fun for you maybe, Tommy,’ Ruth said coldly, still gazing straight ahead of her. ‘You wouldn't think so if it was your possible we'd been looking for.’

‘I think I would,’ Tommy said. ‘I don't see how it matters. Even if you found your possible, the actual model they got you from. Even then, I don't see what difference it makes to anything.’

‘Thank you for your profound contribution, Tommy,’ said Ruth.

‘But I think Tommy's right,’ I said. ‘It's daft to assume you'll have the same sort of life as your model. I agree with Tommy. It's just a bit of fun. We shouldn't get so serious about it.’

I too reached out and touched Ruth on the shoulder. I wanted her to feel the contrast to when Chrissie and Rodney had touched her, and I deliberately chose exactly the same spot. I expected some response, some signal that she accepted understanding from me and Tommy in a way she didn't from the veterans. But she gave me nothing, not even the shrug she'd given Chrissie.

Somewhere behind me I could hear Rodney pacing about, making noises to suggest he was getting chilly in the strong wind. ‘How about going to visit Martin now?’ he said. ‘His flat's just over there, behind those houses.’

Ruth suddenly sighed and turned to us. ‘To be honest,’ she said, ‘I knew all along it was stupid.’

‘Yeah,’ said Tommy, eagerly. ‘Just a bit of fun.’

Ruth gave him an irritated look. ‘Tommy, please shut up with all this “bit of fun” stuff. No one's listening.’ Then turning to Chrissie and Rodney she went on: ‘I didn't want to say when you first told me about this. But look, it was never on. They don't ever, ever, use people like that woman. Think about it. Why would she want to? We all know it, so why don't we all face it. We're not modelled from that sort …’

‘Ruth,’ I cut in firmly. ‘Ruth, don't.’

But she just carried on: ‘We all know it. We're modelled from trash. Junkies, prostitutes, winos, tramps. Convicts, maybe, just so long as they aren't psychos. That's what we come from. We all know it, so why don't we say it? A woman like that? Come on. Yeah, right, Tommy. A bit of fun. Let's have a bit of fun pretending. That other woman in there, her friend, the old one in the gallery. Art students, that's what she thought we were. Do you think she'd have talked to us like that if she'd known what we really were? What do you think she'd have said if we'd asked her? “Excuse me, but do you think your friend was ever a clone model?” She'd have thrown us out. We know it, so we might as well just say it. If you want to look for possibles, if you want to do it properly, then you look in the gutter. You look in rubbish bins. Look down the toilet, that's where you'll find where we all came from.’

‘Ruth’ - Rodney's voice was steady and had a warning in it - ‘let's forget about it and go and see Martin. He's off this afternoon. You'll like him, he's a real laugh.’

Chrissie put an arm around Ruth. ‘Come on, Ruth. Let's do what Rodney says.’

Ruth got to her feet and Rodney started to walk.

‘Well, you lot can go,’ I said quietly. ‘I'm not going.’

Ruth turned and looked at me carefully. ‘Well, what do you know? Who's the upset one now?’

‘I'm not upset. But sometimes you speak garbage, Ruth.’

‘Oh, look who's upset now. Poor Kathy. She never likes straight talking.’

‘It's nothing to do with that. I don't want to visit a carer. We're not supposed to and I don't even know this guy.’

Ruth shrugged and exchanged glances with Chrissie. ‘Well,’ she said, ‘there's no reason we've got to go round together the whole time. If little Miss here doesn't want to join us, she doesn't have to. Let her go off by herself.’ Then she leaned over to Chrissie and said in a stage whisper: ‘That's always the best way when Kathy's in a mood. Leave her alone and she'll walk it off.’

‘Be back at the car by four o'clock,’ Rodney said to me. ‘Otherwise you'll have to hitch-hike.’ Then he did a laugh. ‘Come on, Kathy, don't get in a sulk. Come with us.’

‘No. You go on. I don't feel like it.’

Rodney shrugged and started to move off again. Ruth and Chrissie followed, but Tommy didn't move. Only when Ruth stared at him did he say:

‘I'll stay with Kath. If we're splitting, then I'll stay with Kath.’

Ruth glared at him in fury, then turned and strode off. Chrissie and Rodney looked at Tommy awkwardly, then they too began walking again.