What emerges from Leper's threats in "A Separate Peace"? Chapter 10
Many of the boys at Devon School had threatened to enlist that winter, "but only Leper was serious". A few weeks shy of his eighteenth birthday, Leper chose to join the ski troops rather than wait to be drafted. The results of Leper's fulfillment of his threat to enlist were disastrous.
Leper could not stand up under the rigors of military life; he suffered a breakdown and was released with a Section Eight discharge "for the nuts in the service, the psychos, the Funny Farm candidates". The raw experience of Basic Training was so different from the idealistic perceptions Leper had formed from seeing the recruitment films that he found himself unable to sleep, or eat, or function. He couldn't ever seem "to yell soon enough, or loud enough", and soon Leper began to hallucinate, seeing faces of people he knew on women's bodies, and imagining that a broom carried by another recruit was a man's amputated leg. Leper was sent back home in disgrace, his nerves shot, and his hold on reality tenuous. When Gene goes to visit him, he finds his old friend ruined, with little hope for the future.
In his unstable state, Leper paradoxically speaks the unfiltered truth in many areas. Ominously, he talks about the "savage underneath" within Gene, manifest "like that time (he) knocked Finny out of the tree...like that time (Gene) crippled (Finny) for life" (Chapter 9).