It was the darkness inside him that allowed me into his story. He could not blow his son’s killers to pieces. And the police had arrested nobody. When I came along he saw an opportunity. He would expose a little of himself to me and I would expose his enemy to the world. ‘I have done no wrong,’ he told me several times, ‘so even if you are working for the CIA, I have nothing to worry about.’

He had a lot to worry about. To climb out of the ditch of vengeance into which he had fallen, to gain enough height to see the tale I was bound to tell, was an imaginative journey he could not take. These notes I jotted down – about his living room, his shotgun, about the absence of his wife – were to be enlisted into the story of his terrible relationship with his tenants. However carefully I might write, however alive I might be to historical forces beyond his control, the fact remains that in putting Arthur Mitchell on the page I was asking whether he was responsible for his son’s death.