Peace has returned to Devon with Finny, and Gene's plans for enlistment vanish, almost without a thought. Finny's presence — especially his obvious injury — takes up Gene's entire reality, even the reality of his own future. From now on, Gene responds to Finny's needs, and enlistment, under such circumstances, seems to be desertion of Finny.
But choosing to stay at Devon rather than enlist means saying no to Brinker, a painful rejection that will have consequences later in the Assembly Room "trial." Brinker's needling about Gene's plot to get rid of his roommate is an obvious attempt to keep Gene and Finny's friendship from re-forming. But their caustic wit against Brinker expresses their renewed partnership, despite his "catastrophic joke."
When they mock Brinker together, they define their own friendship against him, reforging their union by excluding the popular leader. Their scorn for Brinker and his plans for enlistment represent a claim for their own shared future. Later, this scorn will turn back on Gene and Finny, though, when Brinker lays a claim on their murky, shared past at the tree.
The boys join together again, but the weeks apart have clearly changed them. Gene has become overly serious — even sanctimonious — about the hardships of wartime, while Finny's frame of mind, his expectations about daily life, remain firmly fixed in peace. At first, Finny's irreverence and flippancy about the war shocks Gene, but soon Finny draws Gene back under his influence, and before long, their relationship of leader and follower re-emerges, even in matters of war and peace.
