Wexley is like any typical small town in America, peaceful, beautiful, and with compassionate people. However, behind this charm, something strange and sinister has crept in and slowly grown. It seems that no one has noticed that the phone lines have been cut and the wealthiest man in town, Grant (played by Michael Rooker), has started to exhibit odd behavior.
But when the farm animals of the townsfolk are horrifically mutilated and young women start mysteriously disappearing, Sheriff Bill Pardee (played by Nathan Fillion) and his team must join forces to uncover the truth of what is invading their once peaceful town. With the help of Grant's wife, Starla (played by Elizabeth Banks), what they must face is a terrifying extraterrestrial life form that seeks to devour every living being on Earth.