Nathan Turner, a member of the Army Reserve, is called up one night. Part of his unit gets sent to Washington, DC, to aid forces in trying to contain a strange virus that is quickly infecting people. As the infected attack a safe zone camp he is assigned to, Nathan ends up saving Chelsey, an eight-year-old girl. After the military bombs DC, he and Chelsey make their way to the harbor to leave. They find a downed helicopter with a mysterious woman...