In 1980s Appalachia, life isn’t easy for Sheila. She endures relentless taunting and bullying at the hands of her classmates; she takes care of her great-aunt, the garden and home, and the rabbits; and forages for mushrooms in the forest, all while her mother works long, back-breaking shifts at the state asylum. But it’s her peculiar little sister, Angie, who worries her the most. Angie is obsessed with nuclear war, Rambo, zombies, a Russian invasion of their community, and the ominous, tarot-like cards that she creates that somehow speak to her. As if all that weren’t enough, Sheila feels an unexplainable weight around her neck. Is it the ancient and strange mountain that they live on that casts its shadow on her, or something or someone else unknown? Unseen?

When a pair of female hikers are brutally murdered on the nearby Appalachian trail, Sheila and Angie find themselves inexorably drawn into the hunt for the killer. As the ever-present threat of violence looms larger, the mountain might be the only thing that can save them from the darkness consuming their home and their community.