John Ray, Jr., Ph.D. writes a Foreword to Humbert's memoir, Lolita, or the Confessions of a White, Widowed Male. Ray explains that Humbert died in jail in 1952, right before he was set to go to trial.
Humbert's memoir begins by describing his childhood in the Riviera, where his father owns a luxury hotel. Humbert has many experiences, chief among them, his mother is struck by lightening. But, more prominently, he falls in love (and deep lust) with a "nymphet" girl-child named Annabel Leigh, who is at the hotel on vacation with her parents. Thwarted consummation of his sexual urges creates a life-long obsession with nymphets.
Humbert receives an education in France and England. He marries Valeria, who ends up leaving him for a Russian cab driver. Receiving an inheritance from an uncle, Humbert moves to the United States. Humbert spends time writing and dipping in and out of mental institutes. He finally decides to settle down in Ramsdale, where he moves in with the widow Charlotte Haze and her nymphet daughter, Lolita.
Humbert fixates on Lolita while barely tolerating her vulgar, middlebrow mother. Disgusted with her daughter's bratty behavior, Charlotte packs Lolita off to Camp Q and issues Humbert an ultimatum: love me or leave me. To stay in Lolita's life, Humbert marries Charlotte. An hysterical Charlotte is hit by a car after reading Humbert's diary and discovering his dark lust for her daughter and deep hatred of her.
Humbert picks up Lolita at Camp Q and spirits her off to The Enchanted Hunters hotel. They have sex, which, according to Humbert, she initiates. A stranger expresses to Humbert his fascination with Lolita; Humbert has no idea who he is, plus it's dark so he can't see him.
Humbert and Lolita spend a year driving all over the United States. Lolita starts getting a little bratty, challenging Humbert's sexual demands; he threatens to send her to an orphanage or reform school if she doesn't straighten up. He also feeds her constant craving for souvenirs, Hollywood movies, and pop cultural junk.
Humbert and Lolita move to Beardsley. He gets a job teaching and she goes to the Beardsley School for girls, run by Mrs. Pratt. Lolita takes up an interest in boys, but is even more eager to join the school play, The Enchanted Hunters. Trying to keep her happy, Humbert consents.
Humbert starts getting nervous about Lolita's fidelity to him, so they go on a trip. This time she plans the itinerary. Along the road, they are shadowed by a man in a red car who resembles Humbert's Uncle Trapp.
Lolita becomes sick and must go into the hospital. While Humbert is back at the motel, Lolita leaves with a strange man. Humbert begins his obsessed hunt for Lolita, tracing back through every motel they visited. He spends years looking for her, during which time he hooks up with a kind-hearted alcoholic named Rita.
Humbert receives a letter from Lolita; he tracks her down to a shanty in Coalmont.
Humbert meets with a very pregnant Lolita, gets the story of her escape with Quilty, begs her to return to him, and gives her money from the sale of the Haze home. Now she can move to Alaska with her working-class husband, Dick.
Humbert tracks down Quilty and kills him in his family home, Pavor Manor. Driving the wrong way down the street, Humbert is arrested. In jail, he writes his memoir.