When Michael was in his twenties, his mother got a letter. Michael's father had died. The family were terribly sorry, they'd only found out themselves weeks before. They'd collected his ashes from the cremation agency and scattered them on the vast training grounds of Camp Pendleton.

'They may be sorry, but why couldn't they have told us when the service was?' Michael's mother looked baffled. Michael did not say: they didn't want us, Mom. They don't want me. They know what happened, and you don't.

Michael had a fantasy that lodged in his brain. He would return to it, even when he lived with Phil in their first full hormonal rush of love. He returned to it even now, when he loved nobody.

His father hadn't died. They made a mistake, and mis-indentified someone else's body. And one night, Michael is at an international biology congress, in LA, and for some reason it's raining, but there is a bar next door to his hotel. Michael doesn't know it's a gay bar, he has no idea. He just goes in to escape the unruffled anonymity of the hotel.

And he's leaning against the bar, and something about all these men together, big and butch or pretty and merry, starts alarm bells ringing. He's just beginning to realize what kind of bar it is, when a warm tender voice behind him says, 'Hello, Michael.'

He turns and his father is there, alive. He's still a big man, white-haired and a bit portly now. His skin is sallow, rather than brown, but he's stylish, all in black, and his eyes sparkle with love and regret. He's braver now, more willing to accept the truth. Michael books him into the room next to his in the hotel and what happens next varies, slightly, according to the scenario.

So what do you want, Michael?

Henry waited until long after Michael had finished speaking. Then he crawled up the bed in blue jeans and brown shirt and snuggled up to him.

'You know, Michael, I saw a TV programme once. There's a syndrome. Brothers and sisters who have never seen each other before, or fathers and daughters who meet for the first time as adults. They often fall in love. It's how we're designed. Either we go for someone who's totally different from us genetically. Or we fall in love with someone close to us genetically, because it's worked before. So it's not that you were perverse or bizarre or sick or just plain dumb. It's what people do.'

Michael was not to be mollified. 'So why doesn't everyone fall in love with their father?'

Henry sighed, and kissed him on the forehead. It was as if they had been lovers for decades, comfortable and relaxed and kind. 'The programme said that what makes the difference is living with them when you're young. You have to know them in childhood. There's a kind of barrier kicks in then. In China they sometimes choose a bride for a baby boy… she's a baby girl… and they grow up together and almost always they hate the thought of getting married. They feel it's incest.'

Michael lay still. 'So what do I do about it?'

'What you're doing now. You talk about it. You put it behind you.'

Michael laid his head on Henry's chest. 'Anything else?'

'You could fall in love with someone.' Henry was smiling at him.

'I tried that. It didn't work.'

Michael's face must have looked forlorn, because Henry suddenly looked forlorn too. 'I know. It hurts.'

It was late again, they had been talking all night, and Michael need to sleep. He looked at Henry's face and a phrase came to him. 'Guardian,' he said. 'Angel.'

'That's right,' said Henry. He bundled Michael closer to him. 'If I stay the night, will you try to sleep?'

'Hmmm mmmm,' promised Michael, and felt himself settle as if sinking into Henry's chest. It must have been all he needed, because in the morning, when he woke, Henry was gone.

Michael went to work the next day feeling bright and happy and alert.

Which was good, because there was a lot to do. The deadline for the next grant application was looming, but there was also the paper he had promised for the congress in America, and several offprints that he really should read. He had even fallen behind simply signing off invoicing and accounts.

He and Ebru charged at the in-tray. She sorted all the piles of paper into different sections, and they went through it, letter by letter, invoice by invoice. He couldn't help hearing a certain note of exasperation in her voice. But there was relief as well.

By the end of the day, all her invoices had been signed. Orders had been approved for stationery, feed, even capital expenditure in the form of a new statistical software package. Ebru was happy and joking again. She even stayed late to get it all in the post.

Michael stayed late too. He got through all of his e-mail. Even after he got rid of the spam there were still forty-six real messages to be answered. He went through his paper in-tray and threw out all the sales pitches for conferences and courses. He bundled up all his journals into his bag to be read. He scanned the employment notices from the university in case there was a post coming up. Ebru stuck her head in through the door.

'My, that is a beautiful desk,' she said. 'It is so nice to see the top of it. You should let people see the top of it more often.'

'It certainly looks good,' Michael agreed.

'So nice and tidy,' she said, and made a kind of pinching gesture with her fingers that Michael did not understand.

On the Thursday night, Michael got a phone call.

'Uh, hullo?' said a voice Michael didn't recognize.

'Yes, hello,' replied Michael cautiously.

'Oh, that is Michael. Hello.' Long pause. 'Sorry, this is Philip, Michael. How are you?'

Philip sounded hesitant, well-behaved and cautious.

'I'm OK, thanks.'

'Look, Michael, I'm sorry to bother you. Are you going to be around this weekend?'

'In general, yes, why?'

Exasperation stirred. Do get on with it, Phil. Michael was disoriented. This was not like talking to Philip at all. It was as if he were talking to a particularly diffident stranger who needed to use his loo.

'Well, we've finally found a place and if it wasn't inconvenient for you, I was wondering if I might finally relieve you of all the things I've left cluttering up your flat.'

Philip sounded like his father, pure Surrey.

There were a hundred questions. Is it a nice flat? Where is it? How on earth did you afford it? Neither of you has any money.

But you don't ask a stranger things like that even if you once were married to him.

They agreed Saturday. 'See you, then,' they said as blandly as possible.

Philip showed up in a white rented van with the real Henry. They were having a row. Neither one of them was used to vans or vehicles and they had no idea where or how to park it.

Phil had gone fluttery and shaken. 'Oh, for God's sake, just leave it parked on the pavement outside the door. We're loading furniture.'

Henry looked worn. 'It's illegal to park on the pavement. We'll get a ticket.'

'So we'll have to pay the fine. I'm not lugging chests round the block!'

Michael was embarrassed and very slightly pleased. He leaned into the window. 'Hello, hi. If you leave your emergency lights flashing, the police are generally pretty good.'

'Hello, Michael,' said Philip, looking relieved.

It was surprisingly good to see him. Michael's heart warmed instantly, and he chuckled. 'How are you, Phil?' It was remarkably like seeing family, a cousin perhaps.

'Oh. Fine. Usually.'

'Hi, Henry,' said Michael. He had to remind himself. This Henry is not exactly the same one I talk to. He's a different copy.

'Hiya,' said this copy of Henry and they shook hands. There was a sense of loss with this Henry. Michael wanted to ask him: do you know that we talk?