Scientists from the planets Teronovaj and Pacienco return to Earth 10,000 years after their pioneering ancestors' departure. Physically altered by the need to adapt to harsh conditions on their planets, they struggle with the prejudice and fanaticism they encounter on an Earth recovering from nuclear holocaust and an ice age. When they become divided and trapped on opposite sides of Earth, crewmembers from the two planets must band together to escape native superstition and violence from pursuing military.