Two French sisters, Hippolyte (20) and Delphine (25), realize the importance of their incestuous love when Delphine finds out that their mother France has planned Hippolyte's arrange marriage by the end of the summer.

Spring 1963. French countryside. Hippolyte (20) and Delphine (25) are two sisters from a provincial bourgeois family. They are secret incest lovers. France, their mother, combines an engagement for Hippolyte with the wealthy Vincent. Coming back from a short trip to Paris, Delphine finds out that France has planned Hippolyte's marriage by the end of the summer. This sparks a conclusion that their love is the most important thing, no matter who comes in their way, even if it is their evil mother.—Les Fleurs du Mal