What had so recently seemed impossible quickly became a necessity. Every time I had a stressful day at work or a bad night with the kids, I recited the name of the place I was going to in my head-the hotel and the city. If I could manage until then, I told myself, I’d be fine. I’d spend that week refreshing my mind and body, repairing all the damage that had been done by years of overwork and refusing to rest. (I am a workaholic, by the way. I didn’t even take any real time off when my children were born-I just worked from home as much as I could for the first six months, sitting at my computer while they slept in their baby-bouncers next to my desk.)

The trip was scheduled for June last year. In March, my boss told me the project had been cancelled. My trip was off, just like that. It’s the closest I’ve ever come to crying in a professional situation. I think my boss could see how disappointed I was because he kept asking me if I was okay, if everything was all right at home.

I wanted to scream at him, ‘Everything is absolutely f ***ing great at home, as long as I can get away from it for just one week!’ I honestly couldn’t imagine how I would manage without the break I’d been banking on. Reconciling myself to going without wasn’t an option. I needed something, a substitute. I asked my boss if he could send me somewhere else. The company I work for does similar sorts of work for many different organisations, so it didn’t seem too unrealistic a request. Unfortunately my boss had no equivalent trip to offer me.

Feeling absolutely wretched, I turned to leave his office, but he called me back. He gave me a stern look and said, ‘If you need to get away, go. Take a week off, go on holiday. ’ I blinked at him, wondering why I hadn’t thought of it myself. He then ruined it by adding, ‘Take the kids to the seaside,’ but I could feel the smile forming on my face. He’d planted a seed in my mind.

I decided I would go away, on my own, without telling anyone. I pretended that the trip had not been cancelled, and booked myself into a spa hotel, safely far away from where I live. I would relax, recuperate, and come back a different person. I didn’t feel guilty for lying to my husband, not at that point. I convinced myself that if he knew he would approve. Once or twice I considered telling him. ‘Oh, by the way, my work trip was cancelled, but I thought that instead I’d go and spend a week lying beside a swimming pool in a white towelling bathrobe. Oh, and it’s going to cost us about two and a half thousand quid-is that okay?’

He might not have minded, but I wasn’t prepared to risk it. And, actually, even if he’d said, ‘Fine, go ahead,’ I couldn’t have done it. I couldn’t have done it openly-left my kids for a week and swanned off to have orange-blossom oil rubbed into my back. I had to lie about it because it seemed so frivolous, so entirely unnecessary. And yet-and I don’t know how to convey to you how much-it was absolutely, desperately necessary for me at that point in my life. I felt as if I might die if it didn’t happen.

I set off on the morning of Friday, 2 June, not even bothering to pack the things I’d have needed if I’d been going on the work trip. My husband would never in a million years notice something I’d left at home and think, Hang on, why hasn’t she taken that? He doesn’t notice anything, which I suppose makes him easy to lie to.

The hotel was unbelievably beautiful. On my first afternoon there, I had a full-body massage (I’d never had one before) and it was like nothing I’d ever experienced. I fell asleep on the table. I woke up six hours later. The therapist explained to me that she’d tried to wake me by shaking a set of bells in front of my face and saying my name, but I was sound asleep. Then she’d read the form I’d filled in at the spa’s reception and seen that I’d rated my stress level, on a scale of one to ten, as twenty, so she decided to let me sleep.

When I woke up, I felt unbelievably different. I wasn’t at all tired. I couldn’t remember the last time I’d felt like that-not since I was at university. All the different parts of my brain felt clean, efficient and ready to go. That night, from the hotel’s plush bar, I phoned my husband. I told him I’d arrived at my hotel. He’d forgotten its name. I told him I would be out and about most of the time and that if he needed to contact me my mobile was the easiest way. But I couldn’t avoid saying the name of the hotel I was supposed to be staying in, a hotel on the other side of the world. And a man heard me.

As I was putting my phone back in my bag, I looked up and saw him watching me. He had dark auburn hair, green eyes, pale skin and freckles. His face was boyish, the sort that will never look old. His drink was in front of him-something short and colourless. I noticed the blond hairs on his forearms. I remember he was wearing a blue and lilac striped shirt with the cuffs rolled up, and black trousers that were moleskin, I think. He grinned. ‘Sorry,’ he said. ‘I shouldn’t have been eavesdropping.’

‘No, you shouldn’t,’ I agreed.

‘I wasn’t,’ he quickly explained, looking a bit flustered. ‘I mean, not deliberately.’

‘But you heard, and now you’re wondering why I lied about where I am.’ I don’t know why, but I told him-about the cancelled work trip, my massage, my six-hour sleep. He kept saying that I didn’t need to explain myself to him, but I wanted to, because my reason for lying, I thought, was about as benign as they come. It was self-defence, basically. I really believed that and still believe it. He laughed and said he knew how hard it could be. He had a daughter too: Lucy.

We started talking properly. He introduced himself to me as Mark Bretherick. He was married to Geraldine, had been for nearly nine years. He told me he was the director of a magnetic refrigeration company, that he made fridges for scientists to use that were much colder than normal fridges-nought degrees Kelvin, which is the coldest possible temperature. I asked him if they were white and square, with egg compartments in their doors. He laughed and said no. I can’t remember exactly what he said next but it was something to do with liquid nitrogen. He said that if I saw one of his fridges, I wouldn’t recognise it as a fridge. ‘It hasn’t got Smeg or Electrolux written on it. You couldn’t put your stuffed olives or your Brie in there,’ he said.

After we’d been talking for a while, it emerged that he lived in Spilling. At the time I lived in Silsford-a short drive from Spilling-and we couldn’t get over the coincidence. I told him about my work, which he seemed to find interesting-he asked me lots of questions about it. He mentioned his wife Geraldine all the time and seemed to be very much in love with her. He didn’t say this, but it was clear she was very important to him. In fact, I smiled to myself because, although he was obviously highly intelligent, he was also one of those men who cannot utter a sentence without it containing his wife’s name. If I asked him what he thought about something (as I did many times, not that evening but later, during the course of our week together), he would tell me, and then immediately afterwards he would tell me what Geraldine thought.

I asked if she worked. He told me that for years she ran the IT helpdesk at the Garcia Lorca Institute in Rawndesley, but that she’d always wanted to stop working when she had a child, and so when Lucy was born she did. ‘Lucky her,’ I said. Although I would hate not to work, I felt a pang of envy when it occurred to me how easy and calm Geraldine’s life must be.

On that first night at the bar, Mark Bretherick said one odd thing that stuck in my mind. When I asked him if he thought I was immoral for lying to my husband about where I was, he said, ‘From where I’m sitting, you seem pretty close to perfect.’

I laughed in his face.

‘I’m serious,’ he said. ‘You’re imperfect, and that’s what’s perfect about you. Geraldine’s a perfect wife and mother in the traditional sense, and it sometimes makes me…’ He stopped then and turned the conversation back to me. ‘You’re selfish.’ He said this as if he found it admirable. ‘Practically all you’ve told me tonight is what you need, what you want, how you feel.’