The 2nd Mass discovers the source for the seemingly endless supply of enemy forces. Hal disobeys his father.

Weaver discovers a shocking truth about an old friend and must decide how to best protect the 2nd Mass. Maggie and Isabella are forced to work together.

Tom's life hangs in the balance as his beamer drifts into space. Tom encounters a surprising guest.

A surprise skitter attack leaves the 2nd Mass without food. In desperation, Maggie, Ben, Pope, and Sara go on a dangerous mission hoping to find supplies.

A mission to procure vehicles and fuel goes awry, and a desperate Pope takes things into his own hands. Cochise shares troubling news with Anne.

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 a hostage. Meanwhile, Tom sets off to rescue Hal.

The 2nd Mass arrives at a safe haven. As the two groups make plans for the final assault on the Espheni, the 2nd Mass begins to realize that things aren't exactly as they seem.

Tom gains a powerful new weapon. Ben puts his life on the line to extract enemy plans. Pope discovers that Tom is alive. Meanwhile, the 2nd Mass must reassess their situation when an unexpected visitor appears.

Injured, Tom takes refuge with a unique family who has distanced themselves from the fight, giving him a glimpse of life without war. Hal and Isabella's romance grows as they search for a missing Tom. 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. And Maggie makes a decision that has consequences for her and the entire 2nd Mass.

The final standoff brings the Masons, the 2nd Mass, and their new allies into the bowels of an iconic American location, wrought with new and unpredictable obstacles. Despite great loss along the way, they must persevere with hopes of once and for all reclaiming Earth and humanity.