Sgt. Cain and Dr. Bell struggle through a post-viral-outbreak in America, trying to return to their home base, Mt. Bethel. The landscape is almost devoid of human life, the former populous new virally transformed into Biophages. On their journey home, Cain and Bell are faced with nightmarish confrontations, testing their loyalty to one another and forcing them to reevaluate their ideas of what humanity really is.