In the poor, isolated town of Whitewood, California, 16-year-old Arch Stanton has a bad job at the local bar and grill that is about to get much worse and, despite his skills with firearms, he may not survive the weekend. Arch’s boss, Fat Ernst, would do anything for a chance at easy money, and when he forces Arch to do some truly dirty work, all hell breaks loose. Suddenly, the customers—infected by vicious, wormlike parasites—begin dying in agonizing pain. As events spiral out of control, decades of bitter rivalries resurface and boil over into three days of rapidly escalating carnage.