In the idyllic small town of Ogden Marsh, Iowa, everyone is gathered for Sunday's baseball game. With a barbeque and a marching band it is a real family attraction. Until one of the farmers shows up wielding a shotgun and murder on his mind and the sheriff is forced to shoot him. It turns out that a military experimental poison has leaked into the groundwater and has begun to turn the inhabitants into murderous crazies. The town's sheriff, his wife, his deputy and a nurse are among the few who have not been infected, and they are forced to work together to try to get out of town alive. Something that becomes almost impossible when the military arrives to clean up any traces of their mistakes.