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.
Two women in a French village during World War 2 anxiously await a letter which may or may not be arriving for either of them.
