In medieval Scotland, Moragh meets with her lover Ianto in the barn behind her cottage. She looks out at the storm and imagines that the Devil is laughing at her, and Ianto calls her back to his side. He asks about her husband, Owen, and Moragh says that she doesn't care. She wonders when the elderly Owen will die of his illness, and hates his obsession with her. Moragh assures Ianto that when Owen finally does die, she'll give the arm to him.
After Ianto leaves, Moragh goes to the house and Owens asks where she was. His wife says she was tending to the hens, and he asks her to come over so he can brush out her hair. Moragh reluctantly goes over, cringing at his touch, as Owen says it's the only thing he can do for her in his condition. When he finishes, Owen says that he will recover, and promises that he'll never leave her. He demands a kiss and pulls her to him. Moragh tolerates the kiss but then flees outside and washes her mouth off with water, moaning in disgust.
Deciding that she's had enough, Moragh crosses the moors to the hut of a local crone, a doll maker. The woman asks what she wants, and Moragh says that she wants a doll to use against her husband. The crone agrees in return for two spring lambs, but warns that if Moragh doesn't pay her, the magic will rebound against her. When Moragh agrees, the crone has her describe Owen in perfect detail to capture his visage on the doll.
Once the crone is done with her work, Moragh returns to the farm with her new purchase. She puts the doll down on the table and listens to the sleeping Owen's raspy snores, and then turns and realizes that the doll has moved. Gasping in horror, Moragh throws it into a bag. Owen screams in horror and yells that he's blind, and Moragh runs to him. When he lets her get water, she takes the doll out of the bag and puts it near the stove, and Owen recovers his eyesight.
Owen eventually dozes off and Moragh decides to end his life. She throws the doll into the fireplace, but the unseasoned wood that the crone used refuses to burn. It smolders in the fire, while in the next room Owen screams in mortal agony. Moragh scraps the doll out of the fire and takes it to the nearby quarry, where she throws it into the stream at the bottom.
When Moragh returns to the farm, she checks and finds Owen's charred corpse in the bedroom. She collapses in shock, and Ianto arrives and wakes her. She explains what happened, and Ianto accuses her of using black magic, and that he never wanted her to murder Owen. Since Moragh didn't destroy the doll, Ianto warns that Owen hasn't truly died, and can't die until they destroy it. He rides off to search, and Moragh runs off after him to the quarry. When she arrives, she hears Owen's voice, calling to her. She moves to the edge of the quarry and the ledge gives way beneath her. She falls into the stream below where the doll is resting... near Owen's charred corpse, which opens its eyes. Owen reaches her, insisting that just like he promised, he'll never leave her.