It's only ten days since Douglas Remfry's release from prison, having served seven years for rape, and now he's dead: naked on a bare mattress in a grubby north London hotel room, his head hooded and his hands tied with a brown leather belt.

Someone knew he was coming out. Someone wanted to mete out some punishment of his own.

And when a second sex offender is found dead, DI Tom Thorne knows he has a vicious, calculating vigilante on his hands...