In the novel’s foreword, the fictional John Ray, Jr., Ph.D., explains the strange story that will follow. According to Ray, he received the manuscript, entitled Lolita, or the Confession of a White Widowed Male, from the author’s lawyer. The author himself, known by the pseudonym of Humbert Humbert (or H. H.), died in jail of coronary thrombosis while awaiting a trial. Ray asserts that while the author’s actions are despicable, his writing remains beautiful and persuasive. He also indicates that the novel will become a favorite in psychiatric circles as well as encourage parents to raise better children in a better world.
In the manuscript, Humbert relates his peaceful upbringing on the Riviera, where he encounters his first love, the twelve-year-old Annabel Leigh. Annabel and the thirteen-year-old Humbert never consummate their love, and Annabel’s death from typhus four months later haunts Humbert. Although Humbert goes on to a career as a teacher of English literature, he spends time in a mental institution and works a succession of odd jobs. Despite his marriage to an adult woman, which eventually fails, Humbert remains obsessed with sexually desirable and sexually aware young girls. These nymphets, as he calls them, remind him of Annabel, though he fails to find another like her. Eventually, Humbert comes to the United States and takes a room in the house of widow Charlotte Haze in a sleepy, suburban New England town. He becomes instantly infatuated with her twelve-year-old daughter Dolores, also known as Lolita. Humbert follows Lolita’s moves constantly, occasionally flirts with her, and confides his pedophiliac longings to a journal. Meanwhile, Charlotte Haze, whom Humbert loathes, has fallen in love with him. When Charlotte sends Lolita off to summer camp, Humbert marries Charlotte in order to stay near his true love. Humbert wants to be alone with Lolita and even toys with the idea of killing Charlotte, but he can’t go through with it. However, Charlotte finds his diary and, after learning that he hates her but loves her daughter, confronts him. Humbert denies everything, but Charlotte tells him she is leaving him and storms out of the house. At that moment, a car hits her and she dies instantly.
Humbert goes to the summer camp and picks up Lolita. Only when they arrive at a motel does he tell her that Charlotte has died. In his account of events, Humbert claims that Lolita seduces him, rather than the other way around. The two drive across the country for nearly a year, during which time Humbert becomes increasingly obsessed with Lolita and she learns to manipulate him. When she engages in tantrums or refuses his advances, Humbert threatens to put her in an orphanage. At the same time, a strange man seems to take an interest in Humbert and Lolita and appears to be following them in their travels.
Humbert eventually gets a job at Beardsley College somewhere in the Northeast, and Lolita enrolls in school. Her wish to socialize with boys her own age causes a strain in their relationship, and Humbert becomes more restrictive in his rules. Nonetheless, he allows her to appear in a school play. Lolita begins to behave secretively around Humbert, and he accuses her of being unfaithful and takes her away on another road trip. On the road, Humbert suspects that they are being followed. Lolita doesn’t notice anything, and Humbert accuses her of conspiring with their stalker.
Lolita becomes ill, and Humbert must take her to the hospital. However, when Humbert returns to get her, the nurses tell him that her uncle has already picked her up. Humbert flies into a rage, but then he calms himself and leaves the hospital, heartbroken and angry.
For the next two years, Humbert searches for Lolita, unearthing clues about her kidnapper in order to exact his revenge. He halfheartedly takes up with a woman named Rita, but then he receives a note from Lolita, now married and pregnant, asking for money. Assuming that Lolita has married the man who had followed them on their travels, Humbert becomes determined to kill him. He finds Lolita, poor and pregnant at seventeen. Humbert realizes that Lolita’s husband is not the man who kidnapped her from the hospital. When pressed, Lolita admits that Clare Quilty, a playwright whose presence has been felt from the beginning of the book, had taken her from the hospital. Lolita loved Quilty, but he kicked her out when she refused to participate in a child pornography orgy. Still devoted to Lolita, Humbert begs her to return to him. Lolita gently refuses. Humbert gives her 4,000 dollars and then departs. He tracks down Quilty at his house and shoots him multiple times, killing him. Humbert is arrested and put in jail, where he continues to write his memoir, stipulating that it can only be published upon Lolita’s death. After Lolita dies in childbirth, Humbert dies of heart failure, and the manuscript is sent to John Ray, Jr., Ph.D.