Based on the epic TNT sci-fi series, Falling Skies is set in a world devastated by Espheni aliens. Their invasion has neutralized the world's power grid and technology, destroyed the world's militaries and killed over 90% of the human population. A handful of survivors, calling themselves the 2nd Mass, band together to fight back. Following the destruction of an Espheni tower, they stumble across the wreckage of an ambushed convoy. Among the survivors is an engineer who claims he can create a powerful weapon that may level the playing field in the fight against the Espheni invaders, but it will require the 2nd Mass to undertake several risky operations to collect all the components. What seems at first to be a routine salvage mission quickly becomes a battle for mankind's very existence.