Rare is the spy thriller that doesn’t have as its central character a spy. Or even a disaffected veteran of some service who imbues the story with cool professionalism or weary cynicism.

So it is a surprise, and a pleasant one, to discover early on in Chris Ewan’s Channel Islands thriller that the main character is a regular bloke, a plumber yet (alas, not named Joe), who stumbles into the mystery of his sister’s death and possible international intrigue, by, of all things, answering a service call.