Madame de Mistival is Eugenie's mother. She tries desperately to shield her daughter from the seedier aspects of life despite her husband's efforts to the contrary. She only allows her daughter to visit Madame de Saint-Ange because her husband beats her into submission. Over the course of The Bedroom Philosophers, Eugenie resolves to murder her. In the Seventh and Final Dialogue, Madame de Mistival enters the scene to retrieve her daughter. Under the direction of Dolmance, the libertines beat and gang-rape Madame de Mistival. At the end of the book, Dolmance's syphilitic servant Lapierre rapes Madame de Mistival, and Dolmance and Eugenie sew closed her vagina and anus. Then, the Chevalier de Mirvel returns her to her husband.