Mr. Prud'homme, a substitute teacher at Devon for the summer, shows up at Finny and Gene's room the next morning to punish them for missing dinner. Finny tells him about their adventures and explains that they had to jump out of the giant tree by the river as part of their preparation for war. Mr. Prud'homme laughs and leaves without disciplining them.
Finny's charm and sense of self get him out of all trouble, rendering all of Gene's worry about rules and regulations worthless.
Gene describes Finny as a unique boy, who somehow was good and kind and also a rule breaker. Gene also thinks the faculty looked fondly on Finny and the rest of the students in their year because they reminded the adults of what peace was like. He describes Finny as the ultimate example of the "careless peace" of youth, even though Finny himself celebrates the war by wearing wild shirts.
Finny is a leader, and someone whom Gene admires and wants to be like. The faculty's sense of war as dreadful contrasts totally with Finny's sense of it as thrilling: the understanding of adults vs. the naïve excitement of youth.
Finny and Gene go to a tea party given by Mr. Patch-Withers, the Devon summer substitute Headmaster. Mr. Patch-Withers's wife notices that Finny is wearing a Devon school tie as a belt. Finny gives an elaborate explanation that gets him out of trouble. Gene is embarrassed that he feels slightly disappointed Finny didn't get punished.
Gene envies Finny's ability to get away with breaking rules. This envy embarrasses him and makes him feel like a bad person. It's the beginning of a sense Gene has that Finny affects him too much.
After the party, Finny and Gene head to the river. On they way they discuss the war in Europe, which feels distant and unbelievable to them. At the river, Finny asks if Gene is still afraid to jump. When Gene says he isn't, Finny proposes they form a club to make their partnership official. They name it the "Super Suicide Society of the Summer Session" and make jumping out of the tree an initiation rite.
Finny's assured sense of self, fed by athletic prowess, makes him blind to the feelings of others. While Finny thinks he and Gene are solidifying their friendship, he doesn't realize Gene's resentment of his questions. Not that this really excuses Gene's resentment of his friend.
Gene and Finny climb the tree. Gene delays for a second, and almost loses his balance. Finny stabilizes him. Later, Gene realizes Finny may have saved his life.
Finny saves his buddy's life. It's a sign of Finny's superior athletic skill and ironically foreshadows what Gene will later do to Finny.