I told him to sod off.

Far from being put off, he said, ‘Listen. Spend the week with me.’ I stared at him, speechless. The week? I’d been wondering whether I even wanted to spend the next ten minutes with him. Plus, I wasn’t sure what exactly he meant. Until he added, ‘I mean, properly. With me, in my room.’

I told him he had a phenomenal cheek. I was quite rude to him. ‘You want a week of sex with someone you regard as worthless before returning to your perfect life with the perfect Geraldine. Bugger off.’ That was what I said to him, pretty much word for word.

‘No!’ he said, grabbing my arm. ‘It’s not like that. Listen, I’ve probably said it all wrong, but… what you said before, about needing to come away this week and sleep and rest because you’d never had the chance before and you wouldn’t again, well…’ He looked as if he was struggling for the right words. He didn’t find them. Eventually his face sort of crumpled and he turned away from me. ‘Forget it,’ he said. ‘You’re probably right. I’ll bugger off, as instructed.’

His vehemence had shocked me, and his sudden dejection was as much of a surprise. He looked as if he might cry, and I felt guilty. Maybe I’d misjudged him.

‘What?’ I asked.

He sighed, leaning over his drink. ‘I was going to say that sleep and rest aren’t the only things you don’t get enough of once you’ve had a child.’

‘You mean sex?’

‘No.’ He almost smiled. ‘I meant adventure. Fun. Not knowing exactly what’s going to happen.’

I couldn’t speak. If only he hadn’t said that, if only he’d said something else, I’d have been fine. I’d have been able to stand my ground.

‘You know, I’m away a lot for work,’ he said. ‘Overnight. Often. One or two nights at a time, once or twice a month. This time it’s a week. And whenever I check into another hotel on my own and throw my overnight bag down on the bed, I think to myself, I don’t know what I want more-sleep or adventure. Should I order dinner in my room, watch telly in bed, get my head down early and wake up late, or should I go down to the hotel bar and try to pick up an exotic woman?’

I laughed. ‘So tonight you opted for the latter.’ Though for him I could hardly have been exotic. I lived less than half an hour’s drive from his house. ‘Didn’t you say Lucy was five?’ I said. ‘She must be sleeping by now.’

He looked miserable, as if he wished I hadn’t said that. ‘I can’t remember the last good night I had,’ he said. He seemed needy, yet at the same time strong and determined. Almost angry. I suppose I found him intriguing.

‘Shit,’ I said. ‘No one warned me it might get worse.’

‘It might.’ Unexpectedly, he grinned. ‘But it could also get better. For a bit. Say, this week. Couldn’t it?’

I had never been unfaithful to my husband before. I never will again. I am not the unfaithful type. I hate the whole idea of infidelity. ‘You’re wasting your time,’ I told him.

‘You can’t, in all conscience, say no,’ he said. ‘I’d be too embarrassed. The only way you can save me from the fate of massive humiliation is by saying yes.’

I knew I ought to be finding him more annoying by the second, but I was starting to like him. ‘Sorry,’ I said. ‘I can’t. I told you, I need to rest. Spending a week with another man-that’d be a big deal for me. It’d send me into panic mode, and I’d go home in a worse state than I was in when I left.’ Part of me couldn’t believe I was taking this seriously enough to give him such a considered response.

‘It could be this week only,’ he said. ‘We wouldn’t have to keep in touch. We’re both happily married, neither of us wants to break up our family. We’ve both got a lot to lose. We’re parents-in other words, nobody expects us to do anything secret or exciting ever again.’

He was right. My best friend, who was and still is single, was always telling me I was prim and proper, just because she occasionally saw me trying to persuade my children to eat broccoli, or changing the TV channel if someone was being hacked to pieces on the screen. She thought I’d become a boring mumsy type, and this idea enraged me. And I found this man-Mark Bretherick-physically attractive, especially when he promised that we could confine our adventurous activities, as he called them, to the daytime and early evening, so that I could still have my seven nights of unbroken sleep.

We didn’t share a room. We never spent a night in the same bed. By ten thirty each evening, we were back in our separate suites. But we ate together, had massages together, sat in the outdoor hot tub and the hammam together-and obviously we did the obvious.

One evening, in the restaurant, he started to cry. For no reason, it seemed. He burst out of there, embarrassed, and when he came back he asked me to forget it had happened. I worried he was starting to fall for me, having second thoughts about not keeping in touch once our week together was over, but he seemed all right again after that, so I stopped worrying.

However terrible it sounds, I didn’t feel guilty. I thought about a book I’d read as a teenager, Flowers for Algernon. I don’t remember who wrote it, but it’s about a retarded man who (I can’t remember how) suddenly becomes clever and fully aware. Perhaps he takes a drug of some kind, or someone experiments on him. Anyway, for a while he is bright enough to realise he was retarded and isn’t any longer. He feels as if a miracle has happened. He falls in love and starts to live a full, happy life. And then the effect of the drug or experiment starts to wear off, and he realises he will soon be retarded again, unable to think clearly-he will lose this brilliant new life that is so precious to him.

That’s how I felt, like that man, whatever his name was. I knew I only had a week, and I had to cram everything into it, all the things my life lacked-rest, adventure, being able to concentrate on myself, my own needs. More importantly, I felt I would be able to do everything I had to do more happily and more efficiently when I got home. I was certain my husband would never find out, and he hasn’t.

And then last night I saw the news. I saw a man who was supposed to be Mark Bretherick, and he wasn’t the same person. Maybe the man I met could only do the things he did-the things we both did-as somebody else, which would be understandable. But, whoever he was, he must have known the Bretherick family well because he knew so much about them-enough to convince me that he was one of them.

The story I’ve just told you might have nothing to do with the deaths of Geraldine and Lucy Bretherick. If it doesn’t, I apologise for wasting your time. But I can’t get it out of my head that the two things might be connected. Geraldine and Lucy Bretherick died several days ago, and my husband tells me it’s been on the news and in the papers every day. I didn’t know this-I don’t think I’ve sat down with a newspaper since my first child was born-but if it’s true then the man I met in the hotel last year is bound to have seen the reports. He will have guessed that by now I know he isn’t who he told me he was. I know this sounds totally crazy, but yesterday somebody pushed me into the road and I was very nearly run over by a bus. Today I was followed by a red Alfa Romeo, registration YF52 DNB.

I’m sorry I can’t tell you the name of the hotel, or my name or any more than I’ve told you. If by any chance you find out who I am during the course of your investigation, please, please contact me at work and do not let my husband find out about any of this. My marriage would be over if he did.

A low, rasping voice from behind me jolts me out of my seat. ‘I see dead people,’ it says. I make an undignified whimpering noise as I whirl round to see who is behind me.

It’s Owen Mellish, my least favourite colleague. My body sags as if it’s been punctured. I turn back to my screen and quickly click on ‘close file’, feeling my face heat up. Owen is laughing loudly and slapping his knee, pleased to have given me a fright. His short, paunchy body, squeezed into a tight green T-shirt and ripped denim shorts, is sprawled in a swivel chair which he rocks back and forth with one of his trunk-like hairy legs.