The countess wants to marry her daughter to Albéric de Marignac, a young cavalry officer, but Elfy has no dowry and his colonel opposes their marriage.

Rivalries and misunderstandings lead Albéric to challenge Hervé to a duel, during which a stray shot wounds Monseigneur, who is then revealed to be a poacher called Eustache Dauphin.

He explained that the starting point was a romantic idea discovered in an old magic book (a young girl on her engagement day falls into a dungeon and finds a treasure) which he then elaborated with the addition of a story about one of the false claimants to the French throne who proliferated in the years following the execution of Louis XVI.

Only after establishing the spirit and mood of the production did he allow himself to consider the technical aspects of filming it[4] The screenplay was written by Louis Chavance in collaboration with Serge de Poligny, and Jean Cocteau wrote the dialogue.

[5] This film along with La Fiancée des ténèbres (1945) have been judged to be the best in the career of Serge de Poligny, sharing their sense of a mysterious and captivating atmosphere.