The story is written in the form of notes by the heroine addressed to the Marquis de Croamaru, whom she asks for help and for this purpose tells him the story of her misfortunes.

The heroine's name is Maria Suzanne Simonen. Her father is a lawyer, he has a great fortune. She is not loved in the house, although she surpasses her sisters with beauty and spiritual qualities, and Susanna suggests that she is not the daughter of Mr. Simonen. Parents offer Suzanne to become a monk in the monastery of St. Mary under the pretext that they went broke and could not give her a dowry. Susanna doesn't want to; she was persuaded to remain a novice for two years, but after the expiration of the term she still refuses to become a nun. She is imprisoned in a cell; she decides to pretend that she agreed, but actually wants to publicly protest on the day of tonsure; for this purpose she invites friends and girlfriends to the ceremony and, answering the questions of the priest, refuses to take a vow. A month later she was taken home; she is locked up; her parents do not want to see her. Father Seraphim (confessor of Suzanne and her mother) with permission of the mother informs Suzanne that she is not the daughter of Mr. Simonen, Mr. Simonen guesses this, so that the mother cannot equate her with her legal daughters, and the parents want to minimize her part of the inheritance, and therefore there is nothing left for her but to accept monasticism. Mother agrees to meet with her daughter and tells her that her existence reminds her of the vile betrayal of Susanna's real father, and her hatred of this man extends to Susanna. The mother wants her daughter to atone for her sin, so she is saving up for Suzanne's contribution to the monastery. He says that after the trick in the monastery of St. Maria Suzanne has nothing to think about her husband. Mother does not want, after her death, Suzanne to bring strife into the house, but she cannot officially deprive Suzanne of inheritance, since for this she needs to confess to her husband.

After this conversation, Susanna decides to become a nun. Lonshan Monastery agrees to take it. Suzanne was brought to the monastery when a certain Madame de Moni had just become abbess - a kind woman, intelligent, well-knowing human heart; she and Susanna are immediately imbued with mutual sympathy. Meanwhile, Suzanne becomes a novice. She often becomes discouraged at the thought that she should soon become a nun, and then runs to the abbess. The abbess has a special gift of comfort; all the nuns come to her in difficult times. She comforts Suzanne. But with the approach of the day, tonsure is often overwhelmed by Suzanne so much that the abbess does not know what to do. The gift of comfort leaves her; she can't say anything to Suzanne. During the tonsure, Susannah is in deep prostration, she does not remember at all what happened that day. In the same year, Mr. Simonen, abbess and mother of Suzanne, died. In the last minutes, the gift of consolation returns to the abbess; she dies, foreboding eternal bliss. Mother before death passes for Suzanne a letter and money; in the letter - a request to the daughter to atone for mother's sin with her good deeds. Instead of Ms. de Moni, the sister of Christine, a petty, limited woman, becomes the abbess. She is fond of new religious movements, forces nuns to participate in ridiculous rites, and revives the ways of repentance, exhausting the flesh, which were canceled by de Moni's sister. Suzanne at every opportunity praises the former abbess, does not obey the customs restored by her sister Christina, rejects all sectarianism, memorizes the charter so as not to do what is not included in it. With her speeches and actions, she captivates some of the nuns and gains a reputation as a rebel. They cannot blame her for anything; then her life is made unbearable: they forbid everyone to communicate with her, they constantly punish her, interfere with sleep, pray, steal things, and spoil Susan’s work. Suzanne is thinking of suicide, but sees that everyone wants it, and leaves this intention. She decides to break the vow. First, she wants to write a detailed note and pass it on to one of the laity. Susanna takes a lot of paper from the abbess on the pretext that she needs to write a confession, but she suspects that the paper went to other notes.

Suzanne, during a prayer, succeeds in handing over the paper to sister Ursula, who is friendly to Suzanne; this nun all the time removed, as far as she could, the obstacles posed by Susanne by other nuns. They search Suzanne, everywhere they look for these papers; the abbess interrogates her and cannot achieve anything. Susanna is thrown into the dungeon and released on the third day. She gets sick, but is recovering soon. Meanwhile, the time is approaching when people come to Lonshan to listen to church singing; since Susanna has a very good voice and musical abilities, she sings in the choir and teaches other nuns to sing. Among her students is Ursula. Suzanne asks her to forward the notes to some expert lawyer; Ursula does it. Suzanne has great success with the public. Some of the laity get to know her; she meets with Mr. Manouri, who undertook to conduct her business, talking with people who came to her, trying to interest them in their fate and acquire patrons. When the community learns of Susanna’s desire to break the vow, she is declared cursed by God; you can’t even touch it. She is not fed, she asks for food, and she is given all sorts of garbage. They scoff at her in every possible way (they broke her dishes, took out furniture and other things from her cell; at night, they make noise in her cell, beat glass, pour broken glass under her feet). The nuns believe that a demon has entered Suzanne, and they inform the elder vicar, Mr. Eber. He arrives, and Suzanne manages to defend herself against the charges. She is called in position with the other nuns. Meanwhile, Susanna’s case is being lost in court. Suzanne is required to wear a hair shirt for several days, scourge herself, and fast every other day. She gets sick; Ursula's sister is caring for her. Susanna’s life is in danger, but she’s recovering. Meanwhile, Ursula's sister is seriously ill and dies.

Thanks to the efforts of Mr. Manouri, Suzanne was transferred to St. Arpajon Monastery. Eutropia. The abbess of this monastery is extremely uneven, controversial. She never keeps herself at the proper distance: either too close, or too far away; then everything permits, then it becomes very harsh. She meets Suzanne incredibly affectionately. Suzanne is surprised by the behavior of a nun named Theresa; Suzanne concludes that she is jealous of the abbess. The abbess constantly enthusiastically praises Suzanne, her appearance and spiritual qualities, poured Suzanne with gifts, relieved of services. Sister Teresa suffers, watches over them; Suzanne can't understand anything. With the advent of Suzanne, all the irregularities of the abbess’s character were smoothed out; the community is enjoying a happy time. But Susanna sometimes seems strange behavior of the abbess: she often showers Susanna with kisses, hugs her and at the same time comes in great excitement; Suzanne, by her innocence, does not understand what is the matter. Once the abbess comes to Susanna at night. She is shivering, she asks for permission to lie under Susanna's bedclothes, snuggles up to her, but then there is a knock on the door. It turns out that this is Teresa's sister. The abbess is very angry, Susanna asks to forgive her sister, and the abbess finally forgives. The time for confession is coming. The confessor of the community is Father Lemoine. The abbess asks Suzanne not to tell him what happened between her and Suzanne, but Father Lemoine himself asks Suzanne and finds out everything. He forbids Suzanne to allow such affection and demands to avoid the abbess, for in her is Satan himself. The abbess says that Father Lemoine is wrong, that there is nothing sinful in her love for Susanne. But Susanna, although, being very innocent, and does not understand why the abbess’s behavior is sinful, still decides to establish restraint in their relationship. Meanwhile, at the request of the abbess, the confessor is changing, but Susanne strictly follows the advice of Father Lemoine. The abbess’s behavior becomes very strange: she walks along the corridors at night, constantly watches Susanna, watches her every step, terribly laments and says that she cannot live without Susanna. The happy days in the community are coming to an end; everything obeys the strictest order. The abbess passes from melancholy to piety, and from him to delirium. Chaos reigns in the monastery. The abbess suffers severely, asks for her to pray, fasts three times a week, and scourges herself. The nuns hated Suzanne. She shares her grief with the new confessor, Father Morel; she tells him the story of her life, talks about her aversion to monasticism. He, too, is fully revealed to her; it turns out that he also hates his position. They are often seen, their mutual sympathy intensifies. Meanwhile, the abbess begins fever and delirium. She sees hell, flames around her, speaks of Suzanne with immense love, idolizing her. She dies in a few months; Sister Teresa soon dies.

Susanna is accused of bewitching the deceased abbess; her sorrows are renewed. The confessor convinces her to flee with him. On the way to Paris, he encroaches on her honor. In Paris, Suzanne lives in a brothel for two weeks. Finally, she flees from there, and she manages to enter the service of the laundress. The work is hard, the food is bad, but the owners are not bad. The monk who abducted her is already caught; he faces life in prison. Her escape is also known everywhere. Mr. Manouri is gone, she has no one to consult with, she lives in constant anxiety. She asks the Marquis de Croamart to help; says she just needs a servant’s place somewhere in the wilderness, in obscurity, among decent people.