Simon Tolkien's latest novel is the third he has written featuring English policeman William Trave. In the first two, set mostly in the late 1950s, Trave is an inspector in the Oxford police department. This new one, though, takes place nearly 20 years earlier, during the London Blitz, and Trave is just another young cop, transferred from Oxford to London, and, in addition to being the assistant to Deputy Chief Inspector John Quaid, has weekend civil defense duties.