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. Tom's decision to have the rebel skitters fight alongside humans creates tension and raises suspicions that someone may be feeding secrets to the enemy. Meanwhile, Hal struggles with nightmares that seem so real, he has difficulty knowing if he's awake or dreaming. And Tom and Anne prepare to welcome their baby.
Falling Skies tells the story of the aftermath of a global invasion by an unknown race of non-humanoid extraterrestrials, referred to as the Skitters, that not only neutralizes the world's power grid and technology, but also destroys the combined militaries of all the world's countries in a short amount of time. 90% of the human population ishuged within a few days.
The story picks up six months after the invasion, and follows a group of survivors who must band together in order to fight back. The group, known as the Second Massachusetts, is led by the retired Captain Weaver and Boston University history professor Tom Mason who, while in search of his son Ben, must put his extensive knowledge of military history into practice as one of the leaders of the resistance movement.