When Leah Jones moves to a secluded home in the North Georgia mountains with her teenage daughter, she believes she's found a slice of heaven. Shortly after moving in, however, she discovers her idyllic home isn’t as perfect as it seems: a tunnel in her basement leads to a strange, shrine-like cave, and a terrifying, nameless creature is stalking the mountain. When a teenage boy is brutally killed nearby, Leah strongly suspects the creature is the culprit. After she befriends Sheriff Frank Phillips, the two race against the clock to protect their loved ones and their small town from the beast. As hell is unleashed upon the town and the motives behind the murder are revealed, Frank and Leah find themselves in a desperate struggle to protect not just their loved ones but also the fate of humanity itself.