CARL JOHNSON, an employee of an aerospace company near Los Angeles, California, is driving north through the desert in the year 2125 on his way to a military base. He observes a flying saucer land in the desert. He tells a friend and fellow worker, NANCY JONES, about it and on a subsequent trip to the military base they investigate the landing site of the flying saucer. A flying saucer is standing there and the two board the ship unseen. The flying saucer lifts off with Nancy and Carl aboard and flies to the Titan moon of the planet Saturn. The people on Titan are among the descendants of 600 people who left earth from near Barstow, California in the year 2000 on two spaceships to colonize a planet in Alpha Centauri. When the colonists arrived in Alpha Centauri they established a colony which they named New Barstow. The colonists argued over politics, economics, and national origin and separated themselves into states. One of the states, New Philadelphia, engaged in a nuclear war with the central government and was forced to abandon its territory due to radioactive fall out. The Philadelphians returned to the earth's solar system in 2115 and set up a base on the Titan moon of Saturn. They established a shuttle service between Titan and earth to carry natural resources to Titan for use in constructing military spaceships that would enable them to return to Alpha Centauri and regain territory. The Philadelphians were technologically more advanced than the United States and the American government had to comply with their demands. However, the government did not notify the American people of the situation for fear that the people would panic. Nancy's fondest wish is to return to earth as soon as possible. Carl adjusts to his situation and wants to study the engines used by the spaceships so that he can use that knowledge when they return to earth. They pose as Philadelphians and Carl soon gets a job in one of the factories. He is eventually found out and Carl and Nancy are put in jail, where they find a hundred other Californians who were caught investigating the space shuttles near Barstow, California. The Philadelphians are ready in 2125 to leave Titan for New Barstow in Alpha Centauri and take along the hundred Californian prisoners. In the ensuing battle between the Philadelphians and the Barstonians, the Barstonians are victorious and put the hundred Californians in a prison on New Barstow. The Californians secretly leave the jail every day and refurbish a spaceship they find in a junk yard. They use that spaceship to return to Titan. The Californians use sleep capsules for the four year trip and the spaceship speed approaches nine tenths the speed of light. They secretly land on Titan and then use several shuttle trips to return to earth. After all one hundred Californians have returned to earth, they tell their story to the newspapers.