The series tells the story of the aftermath of a global invasion by several races of extraterrestrials that neutralizes the world's power grid and technology, quickly destroys the combined militaries of all the world's countries, and apparently kills over 90% of the human population within a few days. 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. Tom gains a powerful new weapon against the Espheni; Ben attempts to extract enemy plans. 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, while the remainder of the 2nd Mass attempts an escape led by Tom. 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. 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.