Chandler's leadership is put to the test when the ship's propulsion system is in danger of breaking down, the crew becomes overworked and exhausted, and Dr. Scott could potentially lose all of her research on the virus.

Rachel and Chandler ask for six volunteers to participate in human trials of her vaccine, but the tests could be a living hell as the virus and the vaccine do battle inside their bodies. Meanwhile back in the States, Chandler’s wife and father are doing everything they can to keep their family alive.

Chandler and his crew finally returns home, where a former D.C. power player is fending off a dangerous warlord who threatens her hopes of restoring law and order in society. Now with a location and a means to finalize their mission, Chandler sets out to save his dying family, only to discover something absolutely terrifying about this brave new world.