In the distant year of 3000, Earth finds itself under the oppressive dominance of the Psychlos, a ferocious race of enormous humanoid aliens who have ruled for a millennium. The remnants of humanity either endure the torment of enslavement in labor camps or struggle to survive in scattered, primitive tribes beyond the reach of Psychlo authority. One such survivor, Jonnie Goodboy Tyler, portrayed by Barry Pepper, ventures from his home in the Rocky Mountains, embarking on a daring quest for discovery.
During his journey, Jonnie allies with Carlo (Kim Coates), a seasoned hunter. However, their expedition takes a disastrous turn when both men are captured by a raiding party of Psychlos and taken to a grim slave camp situated within a colossal dome, constructed over the ruins of Denver, Colorado.
At this dystopian outpost, Terl, the Psychlo security chief played by John Travolta, finds himself trapped in a situation of his own making. Condemned by his higher-ups due to a mysterious incident involving "the Senator's daughter," Terl is forced to devise a strategy to escape Earth by exploiting human labor to extract gold in hazardous, radioactive zones that are hostile to his kind. With the help of his subordinate Ker, portrayed by Forest Whitaker, Terl designates Jonnie as his "foreman," providing him with a rapid-learning machine to acquire the Psychlo education necessary for the task.
As Jonnie absorbs the Psychlos' complex language and history, he starts to plot a rebellion against his captors. Instead of complying with Terl's gold extraction orders, Jonnie cunningly retrieves gold from Fort Knox to meet Terl's expectations. His rebellion gains momentum when he unearths a derelict underground military base stocked with operational aircraft, weapons, fuel, and even nuclear armaments. Using the base's flight simulators, Jonnie and his followers train rigorously in aerial warfare.
After a week of intensive preparation, the rebels initiate a bold uprising against the Psychlos, taking to the skies in Harrier jump jets and armed with an array of weaponry. In a selfless act, Carlo sacrifices his life to destroy the dome covering Denver, leading to the suffocation of the Psychlos who cannot breathe Earth's atmosphere. Seizing a Psychlo teleportation device, Jonnie transports an atomic bomb to the Psychlo home planet, igniting a cataclysmic explosion that obliterates the alien world.
While Ker chooses to align himself with the victorious human rebels, Terl faces a grim fate as he is imprisoned within a vault at Fort Knox. The film concludes with humanity reclaiming Earth but staring into the uncertainty of what lies ahead in their newfound freedom.
