On New Year's Day, a wealthy family is found slaughtered inside their exclusive gated community in north London, their youngest child stolen away. The murder weapon, a gun for stunning cattle before they are butchered, leads Detective Max Wolfe to a dusty corner of Scotland Yard's Black Museum devoted to a killer who thirty years ago was known as the Slaughter Man. But the Slaughter Man has done his time, and is now old and dying. Can he really be back in the game? And was the murder of a happy family a mindless killing spree, a grotesque homage by a copycat killer or a contract hit designed to frame a dying man?