One of Robert Heinlein's most popular (non-Lazarus Long universe, anyhow) books, this is the story of Rod, who is taking the final exam of his survival class, which involves going through a Tunnel, a device which temporarily joins distant places, to an unknown planet and surviving for 3-10 days with only minimal equipment. Unfortunately, something goes wrong, and Rod and his class aren't retrieved on time. Their survival skills face the ultimate test as they must not only survive but learn to coƶperate and form a community, never knowing when or if they'll be rescued.

Excellent story, excellent pacing, excellent characters, excellent book. The whole teacher-marries-student's-sister thing was a little weird, but that is but a minor distraction from a very satisfying whole.