Two crime-scene cleaners find a Huldra (a mythical creature with the body of a beautiful woman and a cow's tail) locked in the cellar of a secluded home, and realize that someone is coming to claim her in this dark fantasy thriller from Norway. Longtime friends Elvis (Erlend Nervold) and Leo (Jon Sigve Skard) have been dispatched to a house deep in the forest to clean up the body of the victime of an animal attack when they discover a secret door in the home. Upon investigating, they find that the door leads to a hidden laboratory in which a fearful woman named Thale (Silje Reinåmo) lies bound in a bathtub, and sustained by feeding tubes. Meanwhile, the audio diaries left by her caretaker offer clues to her mysterious origins. Though the situation turns frightening when a strange figure shows up determined to claim Thale, Elvis and Leo are shocked to find that she is far more powerful than appearances suggest.