To friends and enemies alike, it looks as though Detective Inspector Tom Thorne's career is on the skids. But his situation is not as dire as that of London's homeless.

Three men, sleeping rough on streets paved with anything but gold, have been murdered - each victim kicked to death and found with a £20 note pinned to his chest. Were they killed at random or were they targeted for a reason?

Thorne is seconded to the same streets. Not as a policemen on the beat but as one of life's rejects. It fits: he looks the part - and feels it as well. In a harsh and harrowing netherworld, with its own rules and moral code, Thorne discovers the horrifying link between the homeless victims and the perpetrators of a fifteen-year-old atrocity. Those who know are saying nothing.

But the word on these streets is that the killer is a cop.

A policeman, it seems, was sniffing around long before Thorne came on the scene...