Mimozemská velitelka Diana unikne Odporu a znovu se spojí se svou flotilou. Hvězdné dítě Elizabeth prochází zvláštní metamorfózou.

Diana mluví o míru, zatímco připravuje hrůzostrašnou superzbraň, která by mohla proměnit Los Angeles v trosky. Mezitím bojovníci Odporu aktivují novou vlastní zbraň - ukořistěnou mateřskou loď Visitor.

Kyle Bates se zaplete do Odboje, když se pokouší tajně přesunout Elizabeth do bezpečí v New Yorku. Mike Donovan se probouzí do zdánlivě ideálního života se zprávou, že Země zvítězila nad mimozemskými vetřelci. Bohužel, je to holografická lest návštěvníků zaměřená na získání informací o Hvězdném dítěti.

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.

Sent to investigate Charles' death, newly arrived Inspector General Philip allows Lydia to choose a trial by combat in a laser duel to the death with Diana.

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.