Students don't usually like having to go to school under normal circumstances, so imagine how the students at Kent High School feel considering what's happening to them. While the teens are attending Saturday detention at the school, a chemical plant meltdown causes an explosion of their small town. They survive but are now trapped inside the educational institution -- and they are not alone. Predatory mutant freaks have taken over the school and town, leading to a battle between them and the students. Escape is not an option because venturing outside into the dangerous unknown presents its own life-and-death stakes for the teenagers.