In the end I phoned DS Hollands, in the Domestic Abuse Liaison Office at Camden Police Station, just to bring an end to the argument. When I eventually got through to her, she had completely forgotten who I was. I explained about the curtains and the button, and – stumbling over my words – how this had been typical of Lee’s actions when we’d been together. Even as I said it, it sounded stupid even to me. It sounded like something someone would say just to get attention. I was half-expecting her to tell me off for wasting police time, but in fact she said very little. She said she would phone her contact in Lancashire and would get back to me if there were any concerns.

She didn’t phone back.

That night Stuart didn’t sleep very well. I lay next to him waiting for him to sleep, knowing that he was awake because of the things I’d told him. He deserved better than me. He deserved someone who wasn’t so fucked up, someone who wasn’t trailing a psychopath along with a whole host of other baggage. We lay in bed next to each other in silence, not touching. I wanted to talk some more, but there was no point.

It wasn’t just a button. It wasn’t even just any red button, I was certain of that now. It was a button that came from a dress that I’d worn in another life, another time, with my heart on my sleeve. A dress I’d loved and then hated. And at some point after that, fingers that had once caressed the satin with such a curious, sensual reverence had taken hold of the tiny button and twisted it round and round with force until it had torn away.

When I woke up the next morning, Stuart was already dressed and ready for work. ‘We should go away this weekend,’ he said.

‘Away?’

‘Just for a break. Somewhere out of the city. What do you think?’

In the end we spent the weekend at a hotel in the Peak District, going for long walks during the day, eating too much in the evening and then holding each other in a magnificent four-poster bed, all night. It was a wonderful weekend, and, contrary to expectations, I had no need to fiddle with the curtains.

It was the sort of weekend I would have talked over in great and extensive detail with Sylvia, in years past. Of course that won’t happen now. I sometimes wonder where she is, what she’s doing. It could be that she’s living just up the road from me, and that I pass her house every day. I don’t know where she is. I guess if I phoned up the Daily Mail I could probably find her, but a lot of water has passed under a lot of bridges now, and I don’t know if that is something I could do. Sylvia, although she was my best friend for a long, long time, is part of my old life – the life I was convinced I couldn’t go back to.

I have a new life now, and it’s with Stuart.

Gradually the panic about the red button faded, and going away for the weekend gave me a chance to think about it. To me, there wasn’t any rational explanation of how it came to be in my pocket, so I pretended it hadn’t happened. Maybe Stuart was right – maybe I’d even picked it up myself, in some kind of reverse-psychology absent-mindedness – maybe it was some perverse new symptom of my OCD.

But when we got home I went back to checking, properly. I made a point of going into the flat every morning before work, checking and leaving everything in order, and then checking it when I got home, turning the lights on when it got dark, making it look to anyone who might have been watching from outside that I was home, even when I was upstairs with Stuart. I bought another plug socket timer, and I would turn on the television when I got home from work, leaving it to turn itself off again at eleven o’clock at night. Sometimes I managed to restrict the checking to three times, as per Alistair’s instructions; sometimes it was more.

As for the feeling of being watched – that had never, ever really gone away. Now it was back properly. In every street, every shop, every time I went outside the house, I felt eyes on me. I knew it was my imagination; after all, he was miles away, wasn’t he? He might well have been released at the end of December, but if he was going to come looking for me he would have done it by now.

Part of me wished he’d found some new person to be with, and another part of me hoped he hadn’t, for her sake.