A struggling writer named Clint returns to his hometown to work as a substitute teacher at Fort Chicken Elementary School. On his first day, a mysterious virus, originating from contaminated chicken nuggets, breaks out and transforms the young students into feral, zombie-like creatures with a hunger for human flesh. Clint and his fellow teachers, including the aggressive but well-meaning Wade, the resourceful Lucy, and several eccentric colleagues, must band together to survive the onslaught and escape the school.

As the infection spreads and the students grow more violent, the group of teachers faces increasing peril. They navigate the school's hallways and classrooms, seeking safe haven while trying to understand the nature of the contagion. Along the way, personal conflicts arise, testing their ability to work together and their resolve to protect each other. With limited means of communication and dwindling resources, the pressure mounts as they attempt to find a way out before they too fall victim to the growing horde of infected children.