I've had a dream recently, the same dream, over and over again, and each time I think it's real. I'm back at the ice rink on the afternoon I first met Brendan. The cold stings my face, I can hear the scrape of the blades on the ice and then I see him. He's glancing over at me with that funny look of his, as if he's noticed me and he's got something else on his mind. I see all over again that he's good-looking in a way that not everybody would notice. His hair is glossy black like a raven's wing. His face is oval and his cheekbones and chin are prominent. He has an amused expression on his face as if he has seen the joke before anybody else, and I like that about him. He looks at me and then gives me a second look and he's coming over to say hello. And in my dream I think: Good. I've been given another chance. It doesn't have to happen. This time I can stop it now, here, before it's even begun.

But I don't. I smile at what he says to me, and I say things back to him. I can't hear the words and I don't know what they are, but they must be funny because Brendan laughs and says something, and then I laugh. And so it goes, back and forwards. We're like actors in a long-running show. We can say our lines without thinking, and I know what's going to happen to this boy and this girl. They have never met before, but he is a friend of a friend of hers and so they are surprised that this is the first time they have come across each other. I'm trying to stop myself, in this dream which I both know and don't know is a dream. An ice rink is a good place for a boy and a girl to meet, especially when neither of them can skate. Because they have to lean against each other for support and it's almost compulsory for the boy to put his steadying arm around the girl and they help each other up and laugh at their joint predicament. Her laces are frozen together and he helps her to untie them, her foot in his lap for convenience. When the group starts to break up, it's only natural that the boy asks the girl for her phone number.

The girl is surprised by a moment of reluctance. It's been fun, but does she need something like this at the moment? She looks at the boy. His eyes are shining from the cold. He is smiling at her expectantly. It seems easier just to give him the number and so she does, even though I am shouting for her not to. But the shouting is silent and in any case she is me and she doesn't know what is going to happen – but I do.

I'm wondering how it is that I know what is going to happen. I know they are going to meet twice – a drink, a movie – and then, on her sofa, she'll think, well, why not? And so I'm thinking, if I know what's going to happen, it must mean that I can't change it. Not a single detail. I know they'll sleep together twice more, or is it three times? Always in the girl's flat. After the second time she sees a strange toothbrush in the mug next to hers. A moment of confusion. She will have to think about that. She will barely have time. Because the next afternoon, her mind will be made up for her. It's at about that moment – the girl coming home from work, opening the door of her flat – that I wake up.

After weeks of greyness and drizzle, it was a beautiful autumn afternoon. A blue sky just beginning to lose its electric glare, a sharp wind that was shaking bright leaves from the trees. It had been a long day, and I'd spent most of it up a ladder painting a ceiling, so my neck and right arm ached and my whole body felt grimy and sore, and there were splashes of white emulsion over my knuckles and in my hair. I was thinking about an evening alone: a hot bath, supper in front of the TV in my dressing gown. Cheese on toast, I thought. Cold beer.

So I opened the door to my flat and walked in, letting my bag drop to the floor. And then I saw him. Brendan was sitting on the sofa or, rather, lying back with his feet up. There was a cup of tea on the floor beside him, and he was reading something that he closed as I came in.

'Miranda.' He swung his legs off the cushion and stood up. 'I thought you'd be back later than this.' And he took me by the shoulders and kissed me on the lips. 'Shall I pour you some tea? There's some in the pot. You look all in.'

I could hardly think which question to ask first. He barely knew what job I did. What was he doing, thinking about when I finished work? But most of all, what was he doing in my flat? He looked as if he had moved in.

'What do you think you're doing?'

'I let myself in,' he said. 'I used the keys under the flowerpot. That's all right, isn't it? You've got paint in your hair, you know.'

I bent down and picked up the book from the sofa. A worn, hard-backed exercise book, a faded red, the spine split. I stared at it. It was one of my old diaries.

'That's private,' I said. 'Private!'

'I couldn't resist,' he said with his roguish smile. He saw my expression and held up his hands. 'Point taken, I'm sorry, it was wrong. But I want to know all about you. I just wanted to see what you were like before I met you.' He reached a hand out and gently touched my hair where the paint was, as if to scratch it away. I pulled away.

'You shouldn't have.'

Another smile.

'I won't do it again then,' he said in a playfully apologetic tone. 'All right?'

I took a deep breath. No. I didn't think it was all right.

'It's from when you were seventeen,' he said. 'I like to think of you at seventeen.'

I looked at Brendan and already he seemed to be receding into the distance. He was on the platform and I was on the train which was pulling away and leaving him behind for ever. I was thinking how to say it, as cleanly and finally as possible. You can say, 'I don't think this is working any more,' as if the relationship was a machine that has stopped functioning, some vital bit having gone missing. Or, 'I don't think we should continue,' as if you were both on a road together and you've looked ahead and seen that the road forks, or peters out in rocks and brambles. You can say, 'I don't want to keep on seeing you.' Only of course you don't mean see, but touch, hold, feel, want. And if they ask why – 'Why is it over?' 'What have I done wrong?' – then you don't tell them: 'You get on my nerves,' 'Your laugh suddenly irritates me,' 'I fancy someone else.' No, of course you say, 'You haven't done anything. It's not you, it's me.' These are the things we all learn.

Almost before I knew what I was about to do, I said the words. 'I don't think we should go on with this.'

For a moment, his expression didn't alter. Then he stepped forwards and laid his hand on my shoulder. 'Miranda,' he said.

'I'm sorry, Brendan.' I thought of saying something else, but I stopped myself.

His hand was still on my shoulder.

'You're probably exhausted,' he said. 'Why don't you have a bath and put on some clean clothes.'

I stepped away from his hand.

'I mean it.'

'I don't think so.'

'What?'

'Are you about to get your period?'

'Brendan…'

'You're due about now, aren't you?'

'I'm not playing games.'

'Miranda.' He had a coaxing tone to his voice, as if I were a frightened horse and he was approaching me with sugar on his outstretched palm. 'We've been too happy for you to just end it like this. All those wonderful days and nights.'

'Eight,' I said.

'What?'

'Times we met. Is it even that many?'

'Each time special.'