1920s London. A murder, brutal and bloodthirsty, has stained the plush carpets of a handsome London townhouse. The victim is the beautiful widow Emily French. All evidence points to Leonard, a dashing young chancer who seduced the older woman into leaving him her vast fortune before ruthlessly taking her life. At least, this is the story that Emily's distraught, devoted housekeeper Janet stands by in court.

Romaine, whose testimony was the one hope to save Leonard from the gallows, has turned on him. Nonetheless, Mayhew's firm belief in Leonard's innocence spurs him on with a steely conviction.