The story begins at Grand Isle, a ritzy vacation spot near New Orleans, where Edna Pontellier is summering with her husband and two children. Her husband Léonce is often away on business, so she spends most of her time with a beautiful, shallow friend named Adèle Ratignolle and a charming young man named Robert Lebrun. From the beginning, the reader perceives that all is not harmonious in the Pontellier family: Edna seems bored by her children and frustrated with Léonce, who is silly, ill-tempered, and inattentive (his lavish gifts notwithstanding). Her friendship with Robert, though, has been blossoming. They spend almost every day in each other’s company, strolling on the beach and exchanging quiet jokes and observations.
The third-person narrator, whose voice blends somewhat with Edna’s inner voice, begins to remark on the artificiality of the other women and to question Edna’s habitual obedience to her foolish husband. One night, Edna is moved to tears at a party by the music of Mademoiselle Reisz, a sharp-voiced unmarried woman who most people dislike. Later that same night, Edna conquers her fear of the sea and swims far into the ocean. That night is the culmination of her awakening, her critical, thoughtful examination of the social world and of her inner life. Her friendship with Robert becomes romantically charged. Soon, Robert leaves Grand Isle for Mexico, where he hopes to forget the illicit romance. Edna spends the rest of the summer longing for his company.
In September the Pontelliers return to New Orleans. Edna begins to neglect her household and her children so that she can devote her days to painting, reading, and seeing friends. Her friendship with Madame Ratignolle disintegrates somewhat, but she goes often to see Mademoiselle Reisz, who gives Edna good advice, shows her Robert’s letters (which mention his love for her), and plays beautiful pieces on the piano. Edna’s concerned husband consults with Doctor Mandelet, a wise family friend, who advises him to wait it out. Edna also becomes romantically involved with Arobin, a fashionable young man with a bad reputation. She doesn’t love him, but she is strongly physically attracted to him. Their relationship is a source of confusion and anxiety to her.
Edna’s husband leaves for a long business trip and her children go to stay with their grandmother. She loves her new freedom and decides to move to a smaller house, moving out of her current home and leaving her husband. By selling her paintings, she can become financially independent. She throws a beautiful going-away party, but is troubled throughout by feelings of blankness and despair. One day, Edna learns from Mademoiselle Reisz that Robert is due back in New Orleans. She runs into him at the pianist’s apartment a few days later. He is distant and formal at first, but she convinces him to have dinner at her new house, and soon enough they begin to talk frankly and affectionately. He stays away from her for some time, in a last effort to avoid the affair, but when they run into each other again they return to Edna’s house and confess their feelings openly.
They’re interrupted, however, by an urgent summons from Madame Ratignolle, who is about to give birth. Edna watches the difficult procedure in horror. On her way home, she talks haltingly with Doctor Mandelet about her confused desire for freedom and her aversion to marriage. When she comes home, Robert is gone. He has left a note explaining that he can’t be with her.
Not long after, Edna returns to Grand Isle. She says hello to Victor, Robert’s brother who lives on the island year-round, and walks to the beach. She thinks with despair about her indifference to the world and longs for complete freedom. As she begins to swim, bright and lovely memories from her childhood flicker across her consciousness. In the book’s final, confused moments, as she feels completely free, she drowns.