The double - George P. Pelecanos

The second novel featuring Spero Lucas, a young Iraq vet working as a PI in Washington DC but with a sideline in finding lost items - the kind of items the owners can't go to the police about. This time Spero is trying to find a painting belonging to a sexy young woman who was scammed out of it by a super-smooth con artist, part of a team of ruthless thugs. Spero tracks the painting down but the woman is brutally attacked to warn him off.

Spero goes on the attack and takes the gang out one by one in their isolated house in the woods - prompting the question: have his experiences in Iraq turned him into an amoral killer no better than the crooks he's up against? It's this question that gives the book its dark edge, and moral ambiguity, with a hero we're not quite sure we should like.