Season three of Falling Skies opens seven months after the 2nd Mass arrived in Charleston. In the interim, Tom has been elected to political office, but he has his hands full as the resistance continues to battle the alien invaders.
The Volm discover a power source for Espheni weapons and encourage Tom to seek its destruction. Hal has nightmares involving his relationship with Karen. The loyalty of the Volm is questioned. The team also discover a mole is among them.
The two-year anniversary of the alien invasion is fast approaching as the people of Charleston prepare for another potentially devastating offensive. A sniper attack by an unlikely gunman creates questions and doubts within the new government.
After the people of Charleston defeat another alien attack with the help of new advanced weaponry, and Tom is invited to meet with a powerful leader (guest star Stephen Collins).
When a mission goes terribly awry, Tom and Pope must rely on each other to survive. Meanwhile, Weaver and company search desperately for two members of the 2nd Mass who have gone missing.
Tom uncovers confidential intelligence about the heart of the alien operation. Meanwhile, Charleston prepares to mount an offensive against the Espheni, but a massive explosion brings the operation to a halt.