But still I couldn’t see things that way. I’d drunk so much that even the next morning I remembered little about what happened and the recollections that did remain were quite different. Andrew kissing me. The two of us walking hand-in-hand along the sand as the sun slid up over the horizon again. All the other guests had disappeared by then and we were alone.

‘Do you still have the letter?’ I asked.

‘Malcolm gave it to the newspaper,’ Eileen said. ‘Besides, it was spiteful, horrid. Why would we keep it?’

‘I never wrote it.’ But, even as I said the words, I could hear the uncertainty in my voice. Because by now I wasn’t entirely sure that was true. Another picture slipped into my head. I got to my feet and left the house.

It was still snowing, but not so heavily, and occasionally the clouds parted and there was a moon. I turned the car with difficulty and slithered back to the main road. When I got to the Bod there was a note on the door. It would be from John, checking that I was OK and perhaps inviting me to his chaotic house for supper. At least I hoped that was the case. But when I pulled out the pin and took the note outside, I realized that it was from the stalker again. This time in enormous letters, screaming out at me: GO AWAY SOUTH. YOU’RE NOT WANTED HERE.

That night I decided that I would go. I couldn’t face a month of threats and uncertainty and, besides, perhaps I had found out all that was needed. I got online and booked myself onto the afternoon flight south the following day. I sent a couple of emails, and then brought up the synopsis of my story. It seemed that the plot lines were working out and I had an ending in mind. For the first time since arriving in Shetland I had a few hours’ uninterrupted sleep.

When I woke there was still little light. In winter it takes the sun a long time to reach Scalloway in the west. I made coffee and checked my emails. There was the reply I was waiting for. And the television film had been given the green light by commissioners. My agent was ecstatic: Where are you? We need you back in London. As I drove south, the sun was rising as a huge orange ball to my left. I felt a sudden burst of energy. Soon I would be back in the city, anonymous and safe. There would be no more ridiculous notes to disturb me.

I arrived early and that had always been the plan. I had been organizing this moment for a long time. Certainly before I flew into Sumburgh two days before. Because, deep down, I’d always suspected what had happened to Billy Anderson. My meeting with Eileen had only confirmed it. The narrative of his death had run through my novels, over and over again, driving me a little mad. Now was the time to put an end to that particular haunting.