Why does Leper enlist? And what happens to him?

Leper thinks the video of war looks glamorous and exciting. The video shows a bunch of placid, attractive young men skiing down slopes and passes it off as being part of the war effort; the image reflects nothing like the real realities of war, but nevertheless, Leper is completely hooked by it. Leper leaves a week later, before his 18th birthday, enlisted in the ski troops and perfectly happy to go. Leper ends up going crazy in the army and goes AWOL.