Margit and her older sister, Katla, flee their homeland in Iceland after their mother is killed for practicing witchcraft. Needing a place to stay, Katla casts a spell over a young farmer named Jóhann which makes him fall in love with her, ensuring the wellbeing of herself and Margit. Jóhann's son, Jóhas, sees through Katla's plan and pleads for his father to make her go away. To help Jóhas in his struggle, Margit's mother appears to Margit in visions and provides a magic amulet of protection for the boy. Will Jóhas be able to rid his family of Katla or will she continue to control them with her witchcraft?