A diabólica Diana, capturada e julgada por seus crimes contra a raça humana, é sequestrada pelo magnata corporativo corrupto Nathan Bates, que deseja conhecer os segredos da tecnologia avançada dos Visitantes.

Diana talks peace while readying the fearsome Triax super-weapon that could reduce Los Angeles to rubble. Meanwhile, Resistance fighters activate a new weapon of their own - a captured Visitor mothership.

Kyle Bates becomes involved in the Resistance when they are attempting to secretly move Elizabeth to safety in New York. Mike Donovan awakens to seemingly the ideal life with news that Earth has triumphed against the alien invaders. Alas, it's a holographic ruse by the Visitors aimed at gathering information about the Starchild.

Seeking to free his son Sean from the Visitors, Donovan grapples with an insidious, powerful alien named Klaus.

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.

Led by Donovan, Ham, and Elias, the Resistance runs into a doublecross when they seek to rid a mining community from alien-backed thugs.

When Diana seals off the Open City with an impenetrable force field which destroys humans on contact, Donovan and Ham must kidnap the alien genius responsible for its development.

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.

Ham and Kyle are captured by Visitors, and Charles, the Leader's special envoy, assumes command of the alien forces.

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.

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.

Feeling Diana's presence threatens his power, Charles forces her to marry him, after which Alien law requires she return home.

Needing medicine to treat a deadly diphtheria epidemic, Julie and Kyle recruit a youth gang, one of whom may be a Visitor spy, to help steal the serum.

Anxious to settle a personal vendetta, Philip trails a Fifth Columnist, hoping he will lead him to the Resistance and Donovan.

When Philip and Diana install a high tech computer capable of launching a final victory over Earth, the Resistance's only hope at retaliation is a teenaged computer whiz.

Julie and Donovan sneak aboard the Mother Ship to look for a hidden list naming all the Resistance leaders; Diana schemes to have Lydia's brother slain during a ritual celebration.

The Leader stuns the Visitors by ordering a truce and traveling to Earth to negotiate peace; Diana plots to disrupt the peace.

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.