Season 04, Episode 01 – “Ghost in the Machine”
Season 4 begins with the Masons and the 2nd Mass under brutal attack by a new Espheni war machine and a menacing creation. Before long, the Masons must each establish new relationships and survival techniques.
Season 04, Episode 02 – “The Eye”
Tom faces an impossible decision when the Espheni plan is revealed to him. Meanwhile, Weaver and Pope seek the great escape from the Espheni prison; Matt tries to hide his true allegiance; and Anne searches for her daughter.
Season 04, Episode 03 – “Exodus”
The 2nd Mass orchestrates a complex scheme to escape from the Espheni Ghetto. Meanwhile, Maggie confronts Lexi in Chinatown; Matt tries to dissuade Mira from taking part in a risky escape plan; Anne has a flashback about her time in the Espheni Tower.
Season 04, Episode 04 – “Evolve or Die”
The 2nd Mass finds refuge in a Volm hideout, but tensions rise between humans and the Volm. Meanwhile, Tom teams with Weaver and Cochise in a search for Matt, and Anne reconnects with Lexi.
Season 04, Episode 05 – “Mind Wars”
Tom encounters two enigmatic strangers, who attack his family, then lead him on a violent odyssey. Meanwhile, Hal tries to find a safe place for the remaining Volm and 2nd Mass; and Lexi and Anne clash, triggering perilous consequences.
Season 04, Episode 06 – “Door Number Three”
Tom reunites with his family and the 2nd Mass, but the reunion celebration is cut short when Lexi falls victim to a health crisis. Before long, her illness stirs up tension within the ranks as family members clash over how best to treat her.
Season 04, Episode 07 – “Saturday Night Massacre”
Lexi becomes more powerful and ruthless. Elsewhere, Tom and the 2nd Mass work with the Volm to prevent an Espheni invasion, leading to an all-out battle.
Season 04, Episode 08 – “A Thing With Feathers”
Fallout from a destructive alien attack finds the 2nd Mass picking up the pieces and Maggie fighting for her life. Tom and Dingaan, cut off from the group and buried under rubble, seek possible rescue from an enemy ship.
Season 04, Episode 09 – “Till Death Do Us Part”
Tom and a team track the Volm in an attempt to find equipment to work on a crippled airship. Meanwhile, Maggie and Ben inch closer together at camp while Pope and Sara clash.