In this terrifying glimpse into the "American Dream" gone wrong, an unexplainable phenomenon has taken over the citizens of Ogden Marsh. One by one the townsfolk are falling victim to an unknown toxin and are turning sadistically violent. People who days ago lived quiet, unremarkable lives are now depraved, bloodthirsty killers.

While Sheriff Dutton (Timothy Olyphant) and his pregnant wife, Judy (Radha Mitchell), try to make sense of the escalating violence, the government uses deadly force to close off all access and won't let anyone in or out - even those uninfected. An ordinary night becomes a horrifying struggle for the new remaining survivors as they do their best to get out of town alive.