Scotland Yard superintendent, Richard Jury investigates the murder of wealthy bachelor Billy Maples in a shady London motel. He discovers connections between the murder and the distant past through Maples' grandfather, who served as one of Britain's top code breakers during WWII. Scotland Yard's Richard Jury is drawn into the investigation of a secretive, wealthy bachelor's murder and finds himself coping with a forbidding head detective and too many false leads.