I discovered Billingham's books a few months ago and quickly became a fan. Generally, the DI Tom Thorne series has been smart, funny and well written. In this book, Thorne goes undercover as a "rough sleeper" (homeless person) to catch a killer.
My opinion of this book is divided though. There are certain aspects of this book that I really, really like. But, unfortunately, there is one glaring weakness that really, really bothered me.
First the good. The characters in the book are great. Thorne is his usually self and several of the supporting characters are strong (I particularly liked the relationship between Thorne and Spike, a young homeless man that befriends him). Also, Billingham's take on the culture of London's homeless was interesting. He very much makes you realize that they are human beings, just like yourself. Having lived in London for a couple of years, I also liked the look into what was happening behind the scenes in London's west end.
The flaw, in my opinion, is the fact that there is one, and only one, obvious suspect. Early in the book, we learn that the killer videotaped four English soldiers murdering four Iraqis during the first Gulf War. As these books are structured, you know that the police have "met" the killer sometime during the first third of the book. The problem is, there is only one character you meet that could have conceivably been in Iraq with a video-camera during the Gulf War.
I kept thinking to myself "It can't be him, it would be too obvious, Billingham will come up with a twist at some point", but, no twist is forthcoming, and I became increasingly frustrated by Thorne's failure to even consider the man as a suspect.
All in all, a slight "thumbs up".