Joseph Wambaugh, author of many bestselling police procedurals, is back with a nonfiction look at the curious case of John Orr, a California arson investigator who became a serial arsonist himself. How did the man authorities called "the most prolific arsonist of the twentieth century" finally get tripped up? And what about the novel about arson he seemed to be researching? To get a handle on what motivated the arsonist, Wambaugh interviewed Orr's co-workers -- firefighters who put their lives on the line to combat fires their own colleague had set -- as well as relatives of those who perished in the blazes.