For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Humbert develops a taste for young girls. He earns an education on the continent and marries Valeria in an effort to cure himself and be taken care of. They divorce. Humbert moves to United States and after some peculiar adventures and several stays in a sanitarium, moves to Ramsdale. He becomes a boarder in the Haze household, immediately falling in love with the daughter, Lolita. Desperate to stay near Lolita, Humbert marries Charlotte Haze, who conveniently dies, leaving Humbert to gratify his passion.
Act II
Humbert and Lolita begin their affair. They undertake a year-long trip around the United States, an odyssey filled with cheap motels, souvenirs, and tourist traps. They end up in Beardsley because Lolita has to go to school and Humbert must work. They live together, continuing their torrid affair, but Lolita is getting ornery. Humbert starts to become possessive. He lets her take part in the school play, which makes matters worse. After a big blow-up, Lolita proposes taking another trip. They set off.
Act III
Lolita is kidnapped. Humbert undertakes an extensive effort to find her, but is only tormented by provocative clues that prove nothing other than that her abductor is Humbert's intellectual equal. Finally after several years, and in need of money, Lolita contacts him. Humbert tracks her down, tries to win her back, finds out who she bailed with, gives her money, then leaves to kill Clare Quilty. Humbert shoots and kills Quilty and ends up in jail.