Seven hundred days after U.S. President Austin (Lee Majors) announces a new, rapidly spreading virus, a resulting plague has killed most of humanity and transformed the rest into mutants. The sole survivor, Sarah Teller (Sarati), and her canine companion, Ranger (Max the Dog), struggle valiantly to find a cure and restore the human race. When a mysterious force pulls her to a displaced mansion deep in the Texas hills, however, everything will change, for her, the father she never knew she forgot (Shawn Welling), and the entire world.