Although this is a novel, it is a rather dazzling refraction of fact into fiction. Horowitz with his ingenious mind is playing with the idea of how a writer turns their life experiences and influences via inspiration (for want of a better word) into a narrative - a novel. It is a very entertaining crime novel, with the twist in its concept that the storyteller is Horowitz himself. Written like a memoir the narrative references his life ("fact") as "Horowitz" meets an ex-detective, now consultant to the police, who is investigating a murder and asks "Horowitz" to write about him and the case ("fiction"). The case itself without this extra dimension is clever enough, but although I guessed the murderer fairly early on, "guessed" is the operative word as I had no idea of the unravellings that followed. And the ex-policeman Hawthorne is a classic creation, it has to be said. This could easily be a book too clever for its own good but for the fact that Horowitz is a master writer. Superficially it is huge fun but you can also take it as an investigation of the writer's mind.
I listened to the wonderful Rory Kinnear (whom I've just seen as Macbeth on stage) reading it, and he does so adding even more entertainment value.