The following version of this book was used to create the guide: Mas, Victoria. The Mad Women's Ball. The Overlook Press, 2021.

Victoria Mas's novel The Mad Women's Ball is written from the third person point of view and in the present tense. The novel is set in nineteenth century Paris, France, and follows a largely linear plot structure. The following summary also relies upon the present tense and a strictly linear mode of explanation.

In February of 1885, 19-year-old Eugénie is living with her mother, father, brother, and grandmother in their palatial Parisian apartment. Although she comes from money, Eugénie feels powerless and trapped. She also knows that her father François will never grant her existence consideration or value until she marries. She is not close to her brother Théophile, but feels that he too is limited by their father's patriarchal rule.

Therefore, although Eugénie has been able to see and speak to ghosts for many years, she has never told anyone. She fears that doing so would deem her mad, and result in her internment at the infamous Salpêtrière mental institution. However, one night while tucking her grandmother in for bed, her grandfather's ghost appears to her. He assures Eugénie that it is okay to tell her grandmother the truth. Trusting the ghost, Eugénie reveals everything to her grandmother. She initially seems to accept Eugénie, but later reveals everything to François.

Not long later, François and Théophile take Eugénie to the Salpêtrière and commit her. Although Eugénie tries fighting back, she cannot get free.

Eugénie is Geneviève's newest charge at the Salpêtrière, where she has worked for 20 years. When she first meets the new girl, she disbelieves her father's assertions that she is insane. However, when Eugénie tells Geneviève that she can see and speak to her dead sister Blandine, Geneviève is shaken.

In secret, Geneviève wonders about Eugénie’s claims. When Théophile drops off Eugénie’s The Spirits' Book for his sister, Geneviève takes it home and reads it. The spiritualist text alters Geneviève's formerly fixed beliefs about the world. For the majority of her life, Geneviève has clung to science and medicine for a sense of order. In the wake of reading the controversial text, however, Geneviève starts to believe Eugénie. These newfound beliefs also offer Geneviève a gateway out of her despair and sorrow. Ever since her sister’s tragic death at the age of 16, she has been unable to quell her grief. Believing that Blandine’s presence is close by offers her a balm and a sense of relief.

Geneviève promises Eugénie that she will help her escape. At first, she goes to the doctor and advocates for Eugénie’s release. When the doctor fails to listen to Geneviève's opinion, Geneviève decides to release Eugénie herself. She visits Théophile and invites him to the hospital's upcoming ball. With his help, they can free Eugénie together.

On the night of the ball, Geneviève surreptitiously leads Théophile and Eugénie to the gate. She releases them just as another nurse is approaching. Realizing what Geneviève has done, the hospital staff commits her.

Over the course of the following year, Geneviève settles into her new life as a patient at the Salpêtrière. Although she is essentially trapped, she never felt like a member of the outside world. Meanwhile, Eugénie goes on to use her gift in order to help others.