Mickey refuses to relocate to Europa and David and Pam agree to go instead. They begin their new life in a wondrous habitat where almost anything is possible and the twins, Al (Alpha) and Bet (Beta) are born. The twins have unusual abilities, immense intellects, and quickly mature to the size of human teenagers, but without peers to interact with lack emotional maturity. While David struggles to adjust, Pam takes up a new hobby, using Europan technology to resurrect extinct Earth species including dinosaurs. To occupy themselves, the twins explore Europa using submersibles called aquaskis and make a startling discovery.
The aliens reward Earth with the Sphere, a grapefruit-sized repository of Europan technology. The Sphere promises to usher in a utopian age—a world without hunger and disease, and the need to work. A growing number of humans leave their jobs or drop out of school to join the Sphere Cult. Mickey suspects that the Europans have a hidden agenda, but no one believes him. His girlfriend Vickie tells him he’s jealous because David went to Europa instead of him. When David, Pam, and the twins return to Earth for a visit, Mickey mutilates his palm disc severing himself from the Eurorpans and investigates on his own. He learns a sinister truth, but before he can tell anyone is kidnapped by the Cult and put on trial for his life.