Finn had just given me a charm bracelet. It contained two charms: a rabbit for me and a monkey for him. It was his nickname for me, Rabbit.

‘The silver circle that links the charms,’ he said, ‘is the spirit that joins us.’

‘I’m not sure I believe in spirits,’ I said.

‘I find I can’t do without them,’ he said breezily.

‘How sentimental,’ I replied.

But it was typical of Finn instinctively to sense the language, the context, of whoever he was talking to. Nana appreciated his inclusion of spirits. Nana was very superstitious and, my mother told me, she was also psychic. With her deep grey eyes that glinted over her sharp, hooked nose, she even looked witch-like. When Finn described his relationship with me in this way, she replied as if foreseeing the future.

‘If only that were true,’ she said. ‘If only you, Anna and the spirit that joins you both really were the only three things in your relationship. God bless you.’

At this moment, in the cellar, I pause over another scrap of paper he wrote about us, on some Luxembourg hotel notepad. I’m mes-merised by what he’s written and can almost feel his presence here, through the words.

‘When we make love, and we look into each other’s eyes, I see the child in you, Anna, the spirit in you, and in those moments you are me and I am you.’

It is these brief, aching glimpses of our intimacy that distract me from my task and, to keep my mind away from such thoughts and focused on the present danger, I sit and listen for the slightest sound. Then I slot the gun’s firing pin into the mechanism and slide a single round of green spot ammunition into the chamber. With this weapon, I can kill a man at over two hundred yards.

It is hard enough to keep love safe. In my own experience it is prone either to snap suddenly, or to dwindle and fade to a monotonous daily exercise that is not so different from filling the dishwasher or taking the dog for a walk. I have passionately kissed a man at the start of a film while out on a date at the cinema and, by the end, found him physically repulsive to touch. I have also watched other affairs dwindle imperceptibly to the banal, the everyday, the meaningless.