The next day the narrator and Finny get in trouble for having missed dinner the night before. Mr. Prud'homme, a substitute "master" (or teacher) for the summer session, tries to chastise the pair.
But Finny talks him out of it. He explains charismatically how they were swimming in the river and jumping out of the tree and how on such a beautiful day they just had to have a wrestling match, etc., etc. (He ignores the fact that jumping out of the tree is even more illegal than missing dinner, but that's Finny for you.)
Phineas does this not to avoid punishment, explains the narrator, but to establish some sort of friendliness between himself and the master. Friendliness is "one of Finny's reasons for living."
Besides, he explains, the masters have been a lot more lax this summer of 1942 (as compared to the regular school year). The narrator attributes part of this to Finny – he's completely ignorant of the rules, yet is fiercely loyal to and deeply loves the school. In short, they just don't know what to do with him.
But the narrator identifies a second reason for this lax attitude. These boys remind the masters of what peace is like. They're sixteen, after all, with no draft cards; they're not yet part of the war (that would be World War II).
Back in their room, Finny takes out a pink polo shirt that he decides to wear as an "emblem," though the narrator mocks him for looking "like a fairy."
Finny's been reading the papers, he says, and he saw that the U.S. bombed Central Europe for the first time. That's why he's wearing his new (and very pink) emblem – to celebrate.
While any other boy would've been beat up for such a fashion statement, Finny of course gets away with it, and the narrator is of course irked by this. How come Finny can pull off anything he wants? It just doesn't seem fair.
And then it's time for an afternoon tea at Mr. Patch-Withers' house, along with his wife, conveniently named Mrs. Patch-Withers.
Afternoon tea is not fun. The boys try desperately not to break the teacups, and everyone tries to pretend they're not bored out of their minds.
Finny, as usual, is running the show and charming the pants off everyone. This goes along swimmingly until Mrs. Patch-Withers realizes that Finny is wearing the Devon school tie…as a belt.
The narrator is suddenly excited at the possibility of Phineas getting in trouble.
Phineas talks his way out of it.
Disappointment for the narrator, which he mitigates by congratulating himself on being best friends with such an extraordinary person as Phineas.
On the way home, Finny says he doesn't really believe that the U.S. bombed Central Europe after all. The narrator agrees.
He then explains to his readers. For the boys at Devon, the war was a remote and unreal event. It didn't seem to directly affect them. He's glad of it now, looking back – they were probably one of the few groups who could maintain a sense of peace in the time of war, and he's glad they took advantage of the opportunity.
The boys head to the famous tree, jump off, swim around in the river, same old song and dance.
Then Finny decides they should both jump off the tree to mark initiation into what he's calling "The Super Suicide Society of the Summer Session." The narrator begrudgingly agrees.
While they're in the tree together and moving shakily out onto the branch, the narrator starts to slip. A moment of panic follows, but then Finny reaches out, grabs hold of and steadies him.
Phew, in a word. The narrator realizes that, had he fallen, he would have landed on the ground and perhaps broken his back. Finny practically saved his life, he says.