After the 2nd Mass is separated after an attack on the edge of Charleston, Tom and several others find themselves trying to survive in an Espheni prison camp. Ben awakens to find himself in an idyllic colony under the protection of his sister, and Matt keeps his head down inside a youth re-education center run by the enemy.
Tom's plans to escape the prison camp are complicated when the enemy puts a bounty on his head. Meanwhile Anne acquires a Skitter prisoner, and Ben runs afoul of Lourdes when he tries to get through to his sister.
Tom and the others put their elaborate escape plan into action, knowing that they have zero margin for error. Maggie and Ben confront Lexi publicly, while Matt finds himself in trouble at the Youth Camp when he covers for a friend. Anne draws closer to a family reunion.
The survivors of the prison camp rendezvous with Cochise, who joins Tom and Weaver on a mission to rescue Matt -- unaware that they are being stalked by a creature. Pope strikes out on his own and meets his match, and Anne initiates a confrontation at Lexi's camp.
Tom, Matt, and Weaver encounter two men in the woods, who lead Tom on a harrowing journey and pushes his son to the breaking point. Anne and Lexi clash over the Espheni prisoner, and Hal leads a strategic attack on an enemy Mech.
After the Mason family is reunited at Lexi's colony, Tom and Anne discover that their daughter has entered stasis within a chrysalis. Anne uses regression therapy to regain her memories of her time under captivity by Karen, and Pope stirs up a mob against Lexi.
Lexi leaves the camp in disarray after emerging from her cocoon, and Ben sets out after her. Meanwhile Tom leads the 2nd Mass to head off a new Espheni incursion, leading to major losses for the human resistance.
After an attack devastates the 2nd Mass Hal and Anne go to extreme measures to try and save Maggie's life. Meanwhile, Tom and Dingaan are buried under debris and seek escape inside a crashed alien vessel.
Tom leads a team in search of a cache of Volm equipment to help with an ambitious plan to attack an Espheni power station on the moon. Meanwhile Ben offers to help Maggie learn to deal with her new equipment and abilities, and Matt is reunited with his friend from the youth camp.
While the 2nd Mass learn to pilot the alien airship to strike the enemy power base, personal issues threaten to drive them apart. Elsewhere, Lexi discovers the Espheni's true intentions for her.
Waiting for some sign from the moon mission, the 2nd Mass comes under attack from a terrifying new Espheni weapon. Meanwhile, Tom and Lexi are intercepted and come face-to-face with the alien overlord.