During an argument with her husband James, twenty-eight-year-old Amy Brower, in an uncharacteristic gesture of assertiveness, throws his copy of Milton out the window. She is then stunned when James announces he is divorcing her, and packs up and leaves their home in San Francisco. As her life for the past four years of marriage has revolved around James and his career as a professor of English literature, Amy feels lonely and without direction. In denial and hoping for reconciliation, she evades the questions of her neighborhood greengrocer, the perceptive older widower Joseph Provo, who notices she is not buying as much food. Intensely lonely after the death of his wife of thirty-nine years, the kindly Joseph gives her encouragement and goes along with her story that James is on a business trip. After Amy confides her problem to her friend, Madge Frazier, a strong-minded career woman who works as a seamstress for a modeling agency, Madge arranges for Amy to meet Gert Meredith, the jaded, five-times-married president of the Marin County Divorce League, whose advice is to “Get a job, get a lawyer and get a man.” Soon after, Amy proceeds to an employment agency, where her case worker, sleazy Sherman Cooke, directs her to a job as lifeguard at a swimming pool, a position for which she is barely qualified. Her credit card canceled and lacking a means of support, Amy gamely takes the job, but she is unable to carry out one of its duties, which is to dive off the high board for the weekly exhibition presented by the lifeguard staff. One afternoon after the pool closes, Cooke appears in the women’s locker room and, after she refuses to go out with him, resentfully tries to force himself on her. When he is interrupted by the arrival of one of the neighborhood women, Amy tells him emphatically that she will call the police if she ever sees him again. At Madge’s invitation, Amy attends a cocktail party held at an art gallery honoring avant garde sculptor Marvin Friedlander. Due to Madge's behind-the-scene manipulating, several men approach Amy and start a conversation. Only half-heartedly listening to their chattering, Amy looks across the room and sees Howard Carpenter watching her. Later that night, Howard, who is in town on business for a month, takes her to the apartment where he is staying and she allows him to begin to seduce her. However, she becomes frightened and leaves abruptly, apologizing profusely. Later, Gert refers Amy to Frawley King, a gruff divorce lawyer. Having learned that James is living in Reno, Frawley assures her that she has a strong case against him and asks her to think about what she wants financially from the divorce. Amy, however, only wants her husband back and although Frawley says there are ways of legally forcing James to return to town to protect his interests and his career, he doubts that she can revive the marriage. On Amy’s birthday, Madge drops by with a present and tells her that Howard has been asking about her, but Amy, embarrassed by her earlier behavior, does not want to see him. Before the pool opens one day, Amy climbs up to the high board, but cannot summon the courage to dive. Soon after she encounters Joseph, who invites her to accompany him to a performance of Shakespeare presented in a park. Before she leaves her home, she receives a collect call from James, who is angry about her lawyer’s legal maneuvers. When she finally meets with Joseph for a performance of King Lear , Amy is moved to cry unreservedly on his shoulder. Having guessed that James left her, Joseph encourages Amy to cry until she has no need to cry anymore. When she gets home, she finds Howard waiting and invites him in. This time, she seduces him and they begin a relationship. Ecstatically happy, she tells Joseph about Howard, and Joseph, who has been living with his memories of his wife, becomes thoughtful. Frawley reports that James will be returning for a hearing, but warns Amy that he has been living with a nineteen-year-old woman whom he had been seeing long before he left Amy. Hurt but undaunted, Amy still wants James back, but Frawley bluntly tells her that James does not want her and she needs to decide what is owed her financially. After another cry, Amy confronts Howard, asking him if she is attractive enough, intelligent enough and good at lovemaking, to which he says she is all those things. When she asks if she is good enough to marry, he is surprised and says he did not realize she was interested in marriage at this time. Impatient, she asks if she is the kind of girl he would marry and he answers that she is the kind of girl to whom he is already married. She leaves him, hurt and angry, and calls Frawley, whom she tells to make James pay dearly for his freedom. She then tries to find Joseph, but the store is closed and the neighbors have not seen him lately. As Frawley begins interviewing Amy's friends in order to make a case for financial need and emotional suffering, Amy’s attention is focused on searching for Joseph. She goes to the police, who refer her to the morgue, where a heartless attendant oversees many corpses, among them, the unclaimed body of a young woman about her own age. On the day of her court appointment, Amy ignores Frawley's suggestion to wear no makeup and look “lost,” and tells Madge and Gert that she was "pretty for her wedding" and will be the same for her divorce. On the drive to the courthouse, Amy spots Joseph opening his store. After getting out of the car to greet him, she learns that Joseph has just returned from a Lake Tahoe resort. He explains that he went there alone but made friends. At the courthouse, Amy talks to James, who, acknowledging her victory, says she will get everything she wants and hopes she knows what that is. Pleased to realize that she knows exactly what she wants, Amy tells him that what she wants is his absence. Abruptly, she departs, leaving Frawley to handle the case as best as he can without her. She then proceeds to the swimming pool, where the last lifeguard exhibition of the season is underway, and triumphantly jumps off the high dive.