France, 1757. After Robert-François Damiens attacks Louis XV, the punishment imposed on him and the suspicion surrounding possible accomplices destroy the world of his daughter Gabrielle. Her grievance becomes fixed on the aristocratic Fernard family, whose fate she associates with her father’s abandonment and death. Decades later, the Revolution gives her the power to pursue that revenge as the feared executioner known as Mam’zelle Guillotine.
In Artois in 1794, Gabrielle moves against the surviving Fernards and those who shelter them. Chauvelin sends an investigator to uncover an English rescue network, unaware that the apparently useful agent is Sir Percy Blakeney in disguise. The novel links the spectacular violence of Damiens’s punishment under the old monarchy with the institutionalised executions of the Terror, while Percy attempts to prevent inherited hatred from determining the fate of another family.