In 2007, while on residency in Paris, my partner and I took time out to visit friends in London. It was August, and we were fortunate enough to be offered the opportunity to mind a friend’s mother’s house in Balham Hill. The first night we stayed we were tired; it had been a long day, travelling on the Eurostar with our fifteen-month-old, and so we ordered a pizza, watched television and went to bed early.

I have never been a good sleeper, especially in unfamiliar places, but that night I was asleep almost as soon as my head hit the pillow. For a time I slept undisturbed, but then, sometime deep in the night, I woke, falling out of a deep, dreamless sleep into the sort of strange wakefulness jetlag induces. At first I was disoriented, the room unfamiliar in the darkness. Next to me I could hear my partner breathing. Gradually I realised where I was, but even as I did I was gripped by the certainty I had not woken of my own accord, and that something, somewhere, was wrong.