Bill Slider begins a nightmarish investigation when an unidentifiable victim is found in the no-man's-land beneath a London highway. Slider doesn't have much to go on. The victim, a smartly dressed businessman, has no ID in his pockets and no one has reported him missing. When the autopsy reveals old injuries and faded scars cover the man's body, the mystery only deepens. If he wants answers, Slider knows he must go into London's darkest corners.