There was a large glass case with several familiar pieces of magical paraphernalia: opera hats, decks of cards, red and white billiard balls, wands, handkerchiefs, candles, cups, and so on. A plaster clown stood in one corner – when you walked towards him his face creased magically, and horribly, into a broad smile. There were two weights you could not pick up separately, but which became inexplicably lighter when you lifted them together. Inside one long glass case was a display of dozens of books about magic. Some of these were open at pages showing the way tricks could be prepared and performed. One of them was a large, authoritative-looking tome in solid binding. My habit on seeing a book, any book, is if possible to turn to the front pages to see what inscription is there. Ketty was not watching me. This volume had a handwritten dedication: To my dear son Willer on his sixteenth birthday. The handwriting was squarish, unremarkable, and there was no signature.

Mounted on the walls above and beside the cases were several posters advertising magicians or magic shows from past decades. There were also several photographs of Willer, Dever Antterland, in the middle of his act or posing for a publicity shot.

I regarded these with interest. I still could not help thinking of him as the certain killer of his twin brother, Lew Antterland. From that point of view his work as a magician, entertaining children and families on holiday, was difficult to reconcile. Before seeing this I suppose I had imagined he retreated into the fairground life as a way of cleverly reinventing himself, hiding away in plain sight. Yet as I wandered around the little museum it struck me with some force that Dever Antterland had devoted much of his life to magic. Two large photographs showed him surrounded by smiling and laughing children – one of them was holding a glass tumbler in which a pencil had been mysteriously thrust through the side. Another picture was of three adults sitting around a baize-covered table, watching with rapt attention as he manipulated coins. One of the coins appeared to be hovering above his hand.

Performance magic takes years of dedication, endless hours of rehearsal. You do not take up magic on a whim: it is a lifetime commitment. What was the powerful change that overtook him, I wondered, that converted Willer into a murderer, that made him take the irreversible step into the dark night of the soul?

Ketty was waiting by the door.

The stage on which Willer performed had been at the rear of the room. All trace of it was gone, but the overhead runners where the curtains or stage lights had hung were still in place.