Senior, Casey Williams shelters at her high school with friends and other survivors of the outbreak. They're safe for now, but supplies are running short, and tempers are running shorter. Casey anticipates the looming humanitarian crisis and knows they must find other refuge or face chaos inside. She braves the savage world beyond the school's security fence in an attempt to save herself and her friends. With sheer grit, she leads a small party to find help at the militarized safe zone. Once there, she arranges for her friends to be transported to safety only to learn she's placed them in even greater danger. Determined to seek justice, she fights the living and the undead in her quest to survive in this new dystopian reality.