Deep in New York's upstate wilderness, Ann, a young woman in her late 20's, struggles to survive after a mysterious epidemic decimates society. On the constant brink of starvation, Ann leads an isolated and regimented life. Haunted by memories of her past she also battles the current bloodthirsty threat that lurks just outside of the forests borders, those that the epidemic has infected. When her food stores run dangerously low Ann must make the desperate journey into a nearby town to forage for any remaining food. During one of these raids, a chance encounter brings Olivia, a teenage girl, and her injured stepfather, Chris, into Ann's life and regimen of survival. Learning that Chris and Olivia are trying to go further north, where the infection is supposedly contained, Ann allows them stay at her wooded camp so they can prepare for their journey. Initially reluctant to let her emotional barrier down, Ann relents as Chris's affable nature erases some of the pain the epidemic and her past choices have caused. While Ann and Chris grow close, Olivia becomes bitter, feeling distanced from the man she has depended on for both physical and emotional survival. As an uneasy tension grows, their lives are threatened when the protective forest is breached by the infected. Under attack, Ann is forced to confront her past and make a decision that will irrevocably alter their collective existence and survival.