The naked body of a young woman is found hanging from a tree on a London roadside. Scrawled across her back, the words DIRTY GIRL. Detective Sergeant Stella Mooney and the AMIP 5 squad are faced with a murder as baffling as it is chilling. With no means to identify the victim and no apparent motive, the case is blocked, until... A man is found on a bench by the river, his throat cut back to the vertebrae. And, as before, the killer has left a trademark comment: FILTHY COWARD. Stella and her team can see there's a connection: but what? One victim is a young girl - maybe one of the hookers who work the Strip; the other a researcher for a prominent and controversial MP. More evidence is needed. And soon enough, it comes: another death; another message...