The Director of the Central London Hatcheries leads a group of students 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 Director calls such conditioning “the secret to all happiness and virtue.”
The students and the Director get a special treat when Mustapha Mond , one of the 10 World Controllers, joins the tour. He lectures the students on the World State's creation and its success in creating happiness and stability by eliminating from society all intense emotions, desires, and relationships. In the Hatchery changing rooms, Lenina Crowne , a nurse, is criticized by her friend Fanny for only dating one man, Henry Foster . Acknowledging the need to become more promiscuous, Lenina decides to also date Bernard Marx , even though he is a bit small and strange for an alpha.
Bernard, meanwhile, is outraged as he listens to Henry Foster and another man have a perfectly “normal” discussion about "having" Lenina. Later, in the elevator, Lenina accepts Bernard's invitation to accompany him to the Savage Reservation in New Mexico. 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 exceptional at everything he does that he’s begun to feel stifled.
While Lenina goes on her date with Henry, Bernard attends his biweekly Solidarity Service. After taking soma , the 12 attendees engage in solidarity chants, working themselves into an ecstatic frenzy as they call out to “our Ford ” and then collapse in an orgy. Bernard is miserably aware that he is the only person who didn’t find the Service fulfilling.
The Director signs a permit to allow Bernard to visit the Savage Reservation with Lenina, and as he does so, he reminisces about his own trip to the Reservation 20 years earlier: there was a storm, and his female companion disappeared. Embarrassed to have let slip such information, the Director threatens to reassign Bernard to Iceland. Bernard thinks the Director is bluffing, but just before entering the Reservation, he finds out from Helmholtz that the Director is serious.
In the Reservation, after watching some unnerving Indian rituals, 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 and, when Bernard offers to take him and Linda back to London, exultant at the prospect of seeing the “brave new world” for himself. Bernard, though, plots to publicly humiliate the Director in revenge for his threat of exile. Indeed, the public scandal of having fathered a child forces the Director to resign.
John, "the Savage," is a hit in London society. But he 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, whom they were indulging only in order to meet the Savage. John befriends Helmholtz, reading him Shakespeare while Helmholtz reads him verses that he’s composed himself. Bernard is jealous of their bond.
Lenina, meanwhile, is increasingly preoccupied with thoughts of John, but she can't figure out if John likes her or not. When John finally tells her he loves her, she offers herself to him. He finds the promiscuity of World State society disgusting, however, and curses at her. While she hides in the bathroom, John gets a phone call that his mother is dying.
At the hospital, a drugged Linda thinks her son is her former Indian lover, Popé . This makes John angry, as does the presence of a bunch of Gamma children being conditioned not to fear death. Soon, Linda dies. John, devastated, blames soma for Linda's death, and he interferes with the distribution of soma rations to some Deltas in the hospital lobby. The Deltas start rioting. Helmholtz and Bernard arrive, having been warned what John was doing. Helmholtz joyfully joins the fray in John’s defense, while Bernard remains frozen in indecision. After the riot is quelled, John, Helmholtz, and Bernard are taken to see Mustapha Mond.
In Mond’s office, 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, which is dangerous. Furthermore, happiness sustains mass production, which truth and beauty cannot. The World State has also eliminated the need for God, by smoothing over suffering and abolishing the need for moral effort or virtues. John retorts that he wants the opportunity to suffer, and even to be unhappy.
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 then establishes a hermitage in a rural, abandoned lighthouse, where he purifies himself through sleeplessness, self-flagellation, and other ascetic behaviors. One of his sessions is captured by a photographer, and a sensational film about him released. Soon, hundreds of sightseers show up to see the spectacle for themselves. The crowds beg him to do the “whipping stunt” again. Lenina gets out of one of the helicopters, trying to speak to him, and John rushes at her, calling her “strumpet!” and whipping both her and himself. The intensity of emotion inspires the crowd, including John, to have an orgy, in keeping with World State conditioning. The next day, horrified at what he's done, John hangs himself.