The day of the trip to Amsterdam finally arrives. As Hazel says good-bye to her dad, he tells her that he is “proud.” This comment perplexes her somewhat because she has not really done anything to inspire that feeling. He is tearful during the departure, and she wonders if he is thinking that he might never see her again. It occurs to her that he probably thinks something of that sort every time he leaves for work in the morning.
Hazel’s mom is so excited that she insists on leaving very early. When they show up at Augustus’s house, they overhear him sobbing and shouting at his mother that his life is his own. Hazel wants to continue listening, but her mom insists on returning to the car. From there, Hazel texts Augustus to announce that they are ready to go. Soon he comes outside, looking as cheerful as ever.
Next they head to the airport. At the security checkpoint, Hazel walks through the X-ray machine without her oxygen tank. It is the first time she has taken a step without the tank in years, and she feels oddly free—but afterward she is so dizzy and faint that she feels like she might die.
At the departure gate, everyone stares at Hazel and her oxygen tank. Augustus says he wants to buy himself a hamburger, and he disappears for a full hour, returning only when it is time to board. When they are on the plane, he apologizes and admits that he gets angry when crowds stare like that. He avoided the area because he did not want to put up with the experience.
Before the plane takes off, Augustus gets out one of his cigarettes, and a stewardess tells him that he cannot smoke. Together, he and Hazel explain that he holds an unlit cigarette as a metaphor. The stewardess thinks that over and then says, “Well, that metaphor is prohibited on today’s flight.” Augustus puts his cigarette away.
Not long afterward, he admits that he has never been on a plane before. His sweet excitement charms Hazel. She kisses him on the cheek, an act which thrills him and embarrasses her mother. Hazel insists that the kiss was just friendly.
During the flight, Hazel and Augustus cannot sleep, so they watch movies and chat. When the conversation turns briefly to death, Augustus says that he has researched the number of dead people in the world: 98 billion, or about 14 dead people for everyone who is alive now. He says that every dead person could be remembered if people just organized themselves better.
As the flight continues, the conversation ranges all over, but they talk especially about An Imperial Affliction and poetry. After a while, Augustus whispers “I love you.” Hazel cannot say the words back.