The Director of the Central London Hatcheries leads a group of boys on a tour of the facilities, where babies are produced and grown in bottles (birth is non-existent in the World State). The Director shows how the five castes of World State society are created, from Alphas and Betas, who lead the society, down to the physically and intellectually inferior Deltas, Gammas, and Epsilons, who do menial labor. The Director also shows how each individual is conditioned both before and after "birth" to conform to the moral rules of the World State, and to enjoy his or her predetermined job. Each caste is conditioned differently, but all castes are conditioned to seek instant gratification, to be sexually promiscuous, to engage in economic consumption, and to use the drug soma to escape from all unpleasant experiences.
The boys and the director get a special treat when Mustapha Mond, one of the ten World Controllers, shows up. He lectures the boys on the World State's creation and its success in creating happiness and stability by eliminating from society all intense emotions, desires, and relationships. Meanwhile, Lenina Crowne, a nurse at the Hatchery, is criticized by her friend Fanny for only dating Henry Foster. Lenina decides to also date Bernard Marx, even though he is a bit small and strange for an alpha. Bernard is strange: he is outraged as he listens to Henry Foster and another man have a perfectly normal discussion about "having" Lenina. In the elevator, Lenina accepts Bernard's invitation to accompany him to the Savage Reservation. Bernard then visits his friend Helmholtz Watson. The two criticize the World State. Bernard is dissatisfied because he is self-conscious about being small, while Helmholtz is so perfect at everything that he always feels bored.
The Director signs the permit to allow Bernard to visit the Savage Reservation, and as he does so reminisces about his own vacation to the Reservation twenty years earlier: there was a storm and the woman he was with disappeared. Embarrassed to have told Bernard such information, the Director threatens to reassign Bernard to Iceland. Bernard thinks the Director is bluffing, but just before entering the Reservation finds out from Helmholtz that the Director is serious. In the Reservation, Bernard and Lenina meet a young Shakespeare-quoting savage named John, and his mother, Linda. Bernard realizes that Linda is the woman who got separated from the Director, and that John is their son. John is overwhelmed by Lenina's beauty. Bernard and Lenina bring John and Linda back to London. The scandal of having fathered a child forces the Director to resign.
John, "the Savage," is a hit in London society. But John is troubled by the World State, especially because Linda has drugged herself into a happy stupor with soma. As John's friend and guide, Bernard becomes popular—but when John refuses to appear at one of Bernard's parties, the guests turn on Bernard, to whom they were being polite only in order to meet the Savage. Lenina, meanwhile, can't figure out if John likes her or not. When John tells her he loves her, she offers herself to him. He finds the promiscuity of World State society disgusting and curses at her. While she hides in the bathroom, John gets a phone call that his mother is dying.
At the hospital, Linda thinks her son is her former Indian lover, Popé. This makes John angry, as does the presence in the room of a bunch of Gamma children being conditioned not to fear death. Linda dies. John blames soma for Linda's death, and interferes with the distribution of soma rations to some Deltas. The Deltas riot just as Helmholtz and Bernard, who had heard what John was doing, arrive. John, Helmholtz, and Bernard are taken to see Mustapha Mond.
Mond and John debate World State society. John says it makes life worthless by destroying truth. Mond says that stability and happiness are more important than truth. Mond tells Helmholtz and Bernard that they'll be sent to an island—islands are where all the interesting people who don't like conforming to World State society live—but refuses to let John accompany them. John moves into an abandoned lighthouse, where he purifies himself through self-flagellation. One of his whipping sessions is captured on film, and hundreds of sightseers show up to beg him to whip himself again. One of them is Lenina. John whips her, and himself. The intensity of emotion inspires the crowd, including John, to have an orgy. Horrified at what he's done, John hangs himself.