In a small town in central Oregon, Frank Weaver runs a meth lab out of an abandoned mine. While his young son Aiden waits outside the mine in his truck, Frank and an accomplice are attacked by an unseen creature. Investigating strange noises, Aiden is also attacked by the creature. Frank and Aiden survive their encounter with the creature and return home, where their condition quickly worsens. Frank sets up a locked room and demands that no matter what, Aiden's older brother Lucas keeps them locked inside.