A youth who has known only the primitive life of a galaxy slave is purchased by a beggar who turns out to be a man with many extracurricular activities.

Three teenagers and an older scientist develop their own atomic rocket, solve their own space problems and blast off for the moon in spite of mysterious setbacks.

A high school senior goes through the gate to an unknown planet for a two-to-ten day final exam in Advanced Survival, and realizes, after a period of fighting the elements and wildlife, that something has gone wrong with the gate and what was a brief survival exam is an endless struggle for life.

For a telepathic twin on an exploratory space voyage only a few years pass, yet, when he returns to Earth his brother is ready to celebrate his ninetieth birthday.