In Chapter 9 of Brave New World, we see the tension between the two main characters, Bernard Marx and John the Savage, come to a head. Bernard is a member of the World State, a society in which every aspect of life is carefully controlled and all natural human emotions have been suppressed in the name of social stability. John, on the other hand, is a "savage" who was raised outside of the World State and has never experienced the conditioning that has made the citizens of the World State docile and obedient.
Throughout the novel, Bernard has struggled to fit in with the other members of the World State, feeling like an outsider because of his small stature and nonconformist tendencies. John, meanwhile, has struggled to understand and adapt to the strange and alien society in which he finds himself. The two have formed a bond, with Bernard feeling a sense of superiority over John because of his knowledge of the World State and John looking up to Bernard as someone who can help him make sense of the world.
In Chapter 9, the two characters go on a vacation together to a distant island, where they are free to be themselves without the watchful eyes of the World State. It is here that the true nature of their relationship is revealed. Bernard, who has always felt like an outcast in the World State, finally feels accepted and appreciated by someone, and he becomes possessive of John, wanting to keep him all to himself. John, on the other hand, begins to resent Bernard's attempts to control him and asserts his independence.
The chapter ends with John running away from Bernard and returning to the World State, where he is eventually arrested and sentenced to be "decanted" (killed) for being a "savage." Bernard is left alone on the island, realizing that he has lost his only connection to a world outside of the World State and that he is truly alone.
Overall, Chapter 9 of Brave New World highlights the dangers of trying to control and suppress natural human emotions in the pursuit of social stability. It also serves as a commentary on the dangers of possessiveness and the importance of individuality and self-determination.