Seventeen years ago, Cale Oosha (Lamas), the hereditary ruler of the planet Tyrus, visited Earth for the first time. His uncle the Dragit (Jay) had established an Earth base 30 years previously, with the tacit mission of making peaceful contact and establishing trade. Instead, the Dragit built an extensive underground city, a hidden metropolis aimed at supplying an invasion fleet, ready to pound the warlike Earthlings--particularly the weapons-stockpiling Americans--into submission.
Cale attempted to countermand the Dragit's orders and found himself facing a firing squad. He made a narrow escape with the help of his bodyguard and mentor Rafe, and a human woman named Rita. He and Rita had a child, David, who grew into a strong, solitary teenager. David is aware he's somehow "different," but is ignorant of his past. Rafe, now the sheriff of their small Massachusetts town, knows he's eventually going to have to tell David the whole story--but something is holding him back.