The mutilated corpse of an elderly man is dragged from the Thames. From his hand-made shoes he is identified as Lenny Cobb, an old lag who once testified against the notorious but long dead Kray twins who ruled London's gangland in the 1960s. East End historian Buchan believes it is the first in a series of copycat murders in the style of the Krays and is proved right when another ex-villain who gave evidence against the Krays, Slasher Gainford, is also killed. There is also a resurgence in violent attacks such as the mutilation of young Dan Street in a pub toilet, another hallmark of Kray warning shots. Prime suspect is surly pool hall owner Steven Dukes though Buchan thinks he is not the right sort. Strangely enough his more civilized business associate Jack Cheshire has requested that local officers Chandler and Miles stay on the case, rather than it being given to the organized crime squad.