We walked together from the railway line, the lighthouse ahead of us, standing guard against a hostile sea. Quesnard Cottage stood nearby, dark and solitary, almost silhouetted against a streak of crimson light that had seared itself across a darkening sky. A breeze had sprung up. The trees were writhing and long, wild grass was licking at my feet.

I could tell that Hawthorne was uneasy. He didn’t speak. His eyes were fixed straight ahead. And he smoked – mechanically and apparently without pleasure. He had come to Alderney, he had said, because he wanted to see what had happened to Derek Abbott, but all along there had been much more to it than that and I could see it now. He had the appearance of a man on his way to confront some sort of demon. But was it a demon that he had pushed down a flight of steps in a London police station or one that had entered his life a long time before and which had done him harm in ways that I could not understand? Perhaps I was about to find out.

‘Are you all right?’ I asked as we crossed the main road and entered a track that would bring us to the house.

‘Why shouldn’t I be?’ he snapped back.

‘You just seem very quiet.’

‘I’m thinking.’ We took a few more steps. ‘You know, maybe it would be better if you didn’t join me for this one.’

‘What are you talking about?’ I stopped. ‘Of course I’ve got to be there.’

‘I can tell you what happens.’

‘No! You can’t!’ For a brief moment, I was actually quite angry. ‘I never get any credit from you,’ I said. ‘I never do anything right. I think you forget that you were the one who came to me in the first place, and to be honest, there are times when I wish you hadn’t. But right now I’m stuck with you. I don’t get very much pleasure out of your company, but wherever you go, I’m going too. I’m going to describe what I see and what happens, and assuming you manage to track down whoever killed Charles and Helen le Mesurier, I’m going to describe that too. But it’s my book! You don’t tell me what happens. That’s my job!’

I think that was the most I had ever said to Hawthorne in one breath and he seemed amused. ‘What are you going to call it?’ he asked.

‘The book? I don’t know. Not Hawthorne Investigates.’

‘Well, be careful with this one.’ Hawthorne nodded towards the house. ‘Don’t trust anything he says. Don’t let him get under your skin.’

We continued on our way.