In the POW camp, Billy, Derby, and Lazzaro are taken to a shed inhabited by British prisoners who have been there for years. They are cheerful and energetic, popular with the Germans, and very well-fed, since the Red Cross has sent them ten times too much food as the result of a clerical error. They welcome the Americans with a large feast and a musical performance of Cinderella, which makes Billy laugh so hard that he is taken to the camp hospital. He is tied to the bed and given morphine, while Edgar Derby reads Stephen Crane’s book The Red Badge of Courage to him.

Billy travels in time to another hospital, a mental institution in America where he is a patient after his nervous breakdown in 1948. In the bed next to him is a former infantry captain and alcoholic called Eliot Rosewater. Rosewater introduces him to the work of Kilgore Trout, a science fiction writer, who becomes Billy’s favorite author. Reading Trout’s books helps both men to cope with the meaninglessness of life and to reinvent themselves. Rosewater, however, says that Trout is a bad writer in terms of literary style. This is why his books are not popular, despite the ingenuity of his ideas.

Billy comes unstuck in time and finds himself on display in a Tralfamadorian zoo. The aliens find him beautiful and intriguing, as they have never seen a human before. Then he travels through time again, and is making love to his wife, Valencia, on their wedding night. She always thought no one would want to marry her and promised to lose weight in order to be beautiful for him. Billy has already traveled into the future of their marriage and knows it will be “at least bearable all the way.” Back in the zoo on Tralfamadore, Billy has been given another Earthling as a companion. She is a Hollywood actress named Montana Wildhack, who falls in love with Billy.