Orfin and Borthid have just completed their long journey from earth to Galcon, a planet balanced between two suns. They are met by the ambassador who has been assigned to the planetary outpost. The two are "Discontinueds" which means that they belong to a class of people rendered sterile by a virus which has ravaged earth. Through a lottery set up by the Planetary Council, they have been chosen "Citizen Explorers," and begin a new life on Galcon.
As the story progresses, it becomes clear that things are not as they seem. Behind the personal stories of Orfin and Borthid lies a struggle for control of earth's technologies. The unknown factor is the photosynthoid creatures of Galcon. Dismissed as "Froggies" by the ambassador, Orfin and Borthid see them as the Children of Light. As the two protagonists navigate the terrain of the planet, they discover their identities as Miriam and Paul. They confront their personal demons and emerge whole through the efforts of the shared consciousness of the Children.