Survival is just the beginning . . . After a daring escape, Amy faces a harrowing journey through a post-apocalyptic wasteland in the dead of winter. Pursued by a sadistic killer, she barely makes it out alive. Reunited with Alex at Fort Detrick, she believes the worst is behind her. An audacious rescue attempt leads to disaster. Upon learning the whereabouts of Tara, Saul, and Dylan plan a hasty assault on King's hideout. Defying Nick's orders, they launch the attack only to run into a hail of gunfire. Defeated and demoralized, they retreat back to base forcing Nick to prepare for all-out war.