On the heels of Tom and Lexi's successful (albeit tragic) mission to destroy the Espheni power core on the moon, Tom's life hangs in the balance as his Beamer drifts into space. Back on Earth, Anne reluctantly helps to lead the 2nd Mass in his absence.
When a surprise Skitter attack leaves the 2nd Mass without food, Maggie, Ben, Pope and Sara go on a dangerous mission hoping to find supplies. Meanwhile, Tom and Anne discover the Espheni have created something part Espheni, part Skitter, part Hornet... and part human.
The 2nd Mass discovers the source for the seemingly endless supply of enemy forces. With the Volm's help, Tom's leadership begins to spread across the world, but closer to home, he makes an agonising decision that risks one of their own with repercussions for all.
Cochise shares troubling news with Anne that will test both her medical and leadership skills, whilst elsewhere Anthony's mental stability and loyalties are brought into question. Meanwhile, a desperate Pope takes things into his own hands.
The 2nd Mass leaves Chinatown en route to what they hope will be the final Espheni battle. Along the way, they encounter a deranged and desperate gunman who takes Weaver hostage. Meanwhile, Tom sets off to rescue Hal from Pope and his dangerous group of survivors.
Injured, Tom takes refuge with a unique family who has distanced themselves from the fight, giving him a glimpse of life without war. Meanwhile, the 2nd Mass locates an Espheni device that could be a linchpin to winning the war... if they can figure out how to use it.
Noah Wyle
Tom Mason
Moon Bloodgood
Anne Glass
Will Patton
Weaver
Drew Roy
Hal Mason
Maxim Knight
Matt Mason