It’s the year 3000 AD, and The Psychlos, a race of giant alien beings savagely captured the Earth. For a millennium, Psychlos imprisoned members of the human race for slave labor. The epicenter of their operations is a glass-domed Human Processing Center in Denver, Colorado.
Security Chief Terl is the Psychlo in charge of their Earth base. Terl, a narcissistic sociopath, is permanently assigned to Earth after an incident with the daughter of a Psychlo senator. In order to work his way back into the good graces of the government on Psychlo, Terl and his deputy, Ker, implement an operation to retrieve gold from local mines where the radioactive gases are combustible with the air Psychlos breathe.
Meanwhile, in the nearby Rocky Mountains, tribes of primordial humans live in hiding from “demons” they’ve never actually seen. Jonnie Goodboy Tyler, the bravest and noblest of his tribe, decides it is time to leave his clan behind and explore the surrounding lands. Not far into his journey, Terl’s soldiers capture Jonnie, and bring him to the prison facility.
The rebellious Johnnie continuously fights off and kills the Psychlo guards; perversely convincing Terl that Johnnie is the strongest human and a potential weapon against the leaders on Psychlo. Terl allows Jonnie to learn about human history and speak Psychlo. Johnnie’s education motivates him to overthrow Terl, the entire Psychlo race, and reclaim Earth for all humans. Terl allows Jonnie to lead a party of human slaves into the Rocky Mountains and mine gold over a fortnight.
Jonnie uses his new found knowledge of US History to concoct a scheme where his mining crew will use their 14 day window to fly in a Psychlo ship to For Knox, Kentucky to steal all of the gold abandoned there. The humans deliver the gold bars to Terl, and then proceed on to the abandoned military base at Fort Hood, Texas to acquire jet airplanes, guns, and fuel. While at Fort Hood, Johnnie and the miners use the base’s jet simulators to learn aerial combat in a mere seven days.
The human rebellion launches their multifaceted attack on the Human Processing Center and Planet Psychlo itself. One pilot flies a Psychlo shuttle into the glass dome, destroying it and exposing the Psychlo to the Earth’s atmosphere, killing the aliens. Jonnie uses a Psychlo teleportation machine to send a dirty bomb to Planet Psychlo. Upon its detonation, the dirty bomb’s nuclear waste destroys Psychlo’s atmosphere and, shortly, the entire planet. Jonnie’s human brigade captures Terl, the lone Psychlo survivor, and imprisons him in Fort Knox. There, Terl is surrounded by gold bars, a symbol of his greed and the loss of the Psychlo race. As for the human race, their future is unknown.