Adrien, an attractive dancer whose career was shattered by a motorcycle accident, squanders his youth in idleness. His life changes when he meets Margot, who lives off scams and amorous manipulations.
During a performance at the Château de Blois, an industrialist is murdered as he plays the role of Henri III. Arthur, the young actor playing the Duke of Guise, becomes prime suspect. Police Captain Alice Deschamps heads the investigation with her ex and Arthur's father, Detective Inspector Denis Frécant.