Gene and his friends graduate, and the school lets the military use part of its campus during the summer.
With Finny's innocent influence gone, the school itself becomes a military base...
As the soldiers drive in, Brinker brings Gene to meet his father, who can barely hide his disdain for Gene and Brinker's plans to enter the Navy and the Coast Guard, because neither is dangerous and therefore honorable enough. When his father is gone, Brinker apologizes, and denounces his father's generation for starting a war and making their children fight it.
... and all the boys enlist. But Brinker has been changed. His illusions about war have been stripped away. While refusing to hide from the war, he also now levels Finny's same criticisms against it.
Gene then goes to empty his locker. The locker room has been occupied by some of the soldiers from the Army at Devon for the summer. Gene watches them, and thinks he is ready for the war because he no longer has any hate.
Gene identifies peoples' fear of war and growing up as fear of their own hate, and implies that when people create enemies they are actually battling their own hate.
Gene says all the hatred he felt disappeared with Finny's death. He says only Finny was able to maintain a constant sense of confidence and affection as the world tumbled into war around him. Everyone else—Gene, Brinker, Leper, and Quackenbush—fell prey to the war in his own way, even though it was never clear who the enemy was or if there was an enemy at all.
Gene and his friends have made themselves men by turning people and things into enemies to be defeated. Their selves are then dependent on what they overcame. Only Finny, perfect in youth, never an adult, and always self-sufficient, escaped this sad fate.