Three teenagers from Earth named Laura, Jello, and Vic, are temporarily stranded on the planet Altar, whose inhabitants are being exterminated by the troops of the Reix, the Evil Earth Empire! During a reconnaissance air-bike flight, Laura saves Zarkan, a fierce Altarian warrior with mental powers. After boarding the young, rebellious Earthlings' ship, Zarkan helplessly beholds from space the destruction of his planet... making him the last living Altarian. Zarkan's deep hatred for humans -- and the humans' prejudices toward him -- make for an uneasy alliance, even if Zarkan soon learns his new companions are enemies of the Reix too, the daughter of one of the leaders of the human Resistance and two deserters from the Reix army. After several adventures on various planets, fighting primitive aliens, ruthless bounty hunters, and the Evil Reix, the four rovers finally overcome their differences and prejudices.