The engrossing fourth novel by British TV writer Billingham to feature London police detective Tom Thorne (after 2004&s Lazybones) has a solid, traditional structure and plot, and a whiff of noir sensibility. Thorne is the solid reliable cop whom witnesses trust and colleagues appreciate. Of late, he&s taken in his temporarily homeless pal, pathologist Phil Hendricks, and Billingham has fun with this odd couple (Phil is gay, messy and heavily pierced, Thorne is a Lucinda Williamsloving neatnik). Thorne&s also willing to help out another friend-prickly, middle-aged ex-DCI Carol Chamberlain-who&s uncovered new evidence about a case from the 1980s in which a schoolgirl was set on fire. Moral complexity clouds the picture: the man wrongly imprisoned for that heinous act is a career criminal empathetic Thorne drifts into an affair with a key witness. A second case, equally complex, involves the murder of a Turkish video store owner, which proves to be just one of an alarming series of killings whose pattern Thorne must determine.