Christopher Booker is a scholar who wrote that every story falls into one of seven basic plot structures: Overcoming the Monster, Rags to Riches, the Quest, Voyage and Return, Comedy, Tragedy, and Rebirth.
Plot Type: Voyage and Return
Anticipation Stage and 'Fall' into the Other World
John is brought back to the civilized world
In Brave New World we don't really start this Booker plot until more than halfway into the novel; things get tricky when there's a protagonist shift like you have here. (This is also one of the reasons Brave New World is criticized as being a far-from-perfect novel.) But once you get to Chapter Nine-ish, it's a shoo-in for a "Voyage and Return" discussion. John literally goes from one world to another, and in case you missed it, he explicitly says as much. Also, there's the title.
Initial Fascination or Dream Stage
John is awed with the prospect of visiting "the Other place."
The dream stage doesn't last too long. In fact, it really only lasts the duration of the flight or so.
John realizes that the new world isn't so brave and fabulous after all.
John's disillusionment sets in as soon as he sees the dehumanization in the World State. Clearly, this is not the place for him. The "shadow of oppression" which Booker discusses is particularly clear in the case of Linda, who is essentially enslaved by her dependence on soma.
Lenina throws herself at John, and Linda dies.
Lenina revealing herself as a complete "strumpet" really pushes John to the edge. But it's Linda's death, and more importantly, the callous reaction of others to her death, that pushes him over it. John's soma-destroying freak-out is the summation of his Nightmare Stage.
Thrilling Escape and Return…
…Or lack of thrilling escape and return…
John tries to make an escape by secluding himself at the lighthouse, but his self-mutilation there distorts what ought to be a return to normalcy, to his own world. His death may be thrilling, but it isn't exactly an escape and return. Or is it? If John defined the difference between the two worlds as being that of suffering and the absence of suffering, then his death was either the ultimate form of self-punishment, or the ultimate escape from suffering. What do you think?
Three-Act Plot Analysis
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.
The three acts of Brave New World can be marked roughly by the changes in setting. The first act, therefore, runs from Chapter One up though Part Two of Chapter Six, and it takes place in the civilized world of London.
It follows that Act II covers Bernard and Lenina's time in the Savage Reservation: Chapters Seven, Eight, and Nine. It is during Act II that we have our protagonist switch from Bernard to John.
The last act begins right around the time John is puking his guts out in response to the new world. The transition from Act II is his shifting opinion of the nature of society, from admiration to disgust.