The evil Diana, captured and set to stand trial for her crimes against the human race, is kidnapped by corrupt corporate magnate Nathan Bates, who wants to know the secrets of the Visitors' advanced technology.
Immune to the effects of the red dust bacteria, Diana activates her unstoppable Triax superweapon to reduce Bates and the city of Los Angeles to rubble.
Donovan and Ham are imprisoned in a Visitor work camp guarded by a hideous alien monster; Nathan Bates mounts a desperate search to find the "star-child" to exchange for his son Kyle who's in Diana's custody.
While the Resistance seeks to help Elizabeth escape from Los Angeles, Diana captures Mike Donovan in an elaborate scheme to learn Elizabeth's whereabouts.
With a blood sample from the "star-child," Diana creates an uncontrollable and deadly clone which seeks out Elizabeth; Bates tests Julie's loyalty when he suspects she is sympathetic to the Resistance whose headquarters he is preparing to destroy.
The Resistance, led by Donovan, Julie, and Ham, stage a daring sabotage at a convention of Visitor commanders in a seaside estate where Diana intends to show off the ultimate device in processing humans for food.
While Bates remains in a coma Charles plots to overthrow him. Elsewhere, Willie is gravely wounded so the rebels kidnap a medical student of the Visitors.
A small group of resistance sympathizers (Robin included) are arrested by Bates' police, and a prisoner will be handed over to the Visitors to be executed every day until Donovan, Ham, and Julie surrender.