Suzanne Simonin, a young woman coerced into religious life by her parents, struggles to escape the physical and psychological confinement of the convent. Forced against her will to take holy orders, Suzanne navigates a series of oppressive institutions where she encounters varying degrees of cruelty, manipulation, and isolation. Her objective is to secure her freedom and reclaim her autonomy, a goal that pits her against the rigid, patriarchal structures of the church and her own family. The narrative framework utilizes an epistolary style, presenting the story as a series of accounts that detail the protagonist's harrowing experiences within the cloister walls. The world is defined by the stark contrast between the perceived sanctity of the convent and the harsh, often sadistic realities hidden from the outside world.

Readers and critics frequently analyze the work as a biting critique of institutional intolerance and the suppression of individual liberty. Discussion often centers on the unsettling nature of the convent environment, which Diderot portrays with a blend of realism and psychological intensity. Many observers highlight the effectiveness of the epistolary format in creating a sense of intimacy and urgency regarding Suzanne's plight. The inclusion of the author's prefatory material is often cited as a critical component that shifts the reader's perception of the text from a simple narrative to a complex philosophical inquiry. The work remains a subject of debate due to its provocative themes and its enduring relevance in discussions regarding systemic oppression.