By chance, Tom, a young man from California, meets Coker, the spaceship captain from Ponlenia, an advanced civilization a million light-years away. Coker invites Tom to visit Ponlenia. During a one-year trip, Tom learned a lot of modern knowledge from computers. When they temporarily stay on another terrestrial planet, Edia, Tom follows Coker to do things and meets a young man named Hanson, who looks a lot like Tom. The two young men have a very...