Farmer Frank Larsen hears a noise in his barn and sees a doll sitting on a hay bale. Suddenly, Lucinda Strickland, a crone with white hair and scarred face, steps out of the darkness with a pitchfork, kills him, and knocks over a lantern that sets the barn on fire. The old woman stumbles into the nearby Strickland farmhouse, where Melissa Strickland eats supper with her “parents,” Luther and Molly Strickland. Meanwhile, Jodie Lee Thompson, a young man, drives his Ford Mustang from Austin, Texas, to San Francisco, California. As he stops for gas, the station attendant idly tells him a maniac killed a farmer down the road with a pitchfork. As Jodie continues along the highway, he turns onto a dirt road that leads to a pond, where he relaxes among trees and eats a sandwich. Melissa Strickland appears and invites Jodie to her nearby walnut ranch. When Melissa introduces him to Luther and Molly, her father pulls her aside to complain that she doesn’t have the right to invite a stranger. He asks if she “called” Jodie, and wonders how the young man will react to Lucinda. Melissa insists that Luther be hospitable, so he offers Jodie a drink of homemade cider. After dinner, Jodie wants to leave, but Melissa offers him a place to sleep in the sewing room. As they take an evening walk in the woods, Jodie says he is on a journey to clear his head, while he considers his father’s demand that he go to law school. Melissa admires his freedom and wishes she could fly away. They kiss, and she asks him to stay for a few days because she is lonely. That night, as Jodie sleeps in the sewing room, Lucinda wakes him, tells him, “Go away,” and leaves. When Jodie goes to Melissa’s room, she says Lucinda is her great-grandmother who harmlessly wanders the house at night. Melissa goes to Lucinda’s room and tells her to sleep, but Lucinda instead sits in front of a mirror with her doll. Her reflection changes briefly to the face of a young woman. The next day, Melissa gets her parents’ permission to go to the store. As she and Jodie drive away, Deputy John Mason arrives and asks Luther if he can look around, since Frank Larsen’s farm abuts theirs. In town, as Jodie and Melissa visit a general store, he notices the townspeople are cool toward her, and she explains that they think she is a witch, which is true, she adds. On the way home, she takes him to a field of flowers where she maintains a private shed and invites him inside. The shed has chairs, a bed, and photographs on the wall. Suddenly Luther enters, and Melissa asks if he is looking for Lucinda again. Nearby, Deputy Mason finds a pitchfork in a field, as Lucinda watches from behind a tree. She follows him to his cruiser and kills him with a baling hook. The others arrive moments later, and as Luther, Molly, and Melissa lead Lucinda into the house, Jodie vomits. Luther returns outside, takes the key out of Jodie’s ignition, binds him with the deputy’s handcuffs, and locks him in the barn. Driving the Mustang, Molly follows Luther in Deputy Mason’s cruiser, which they leave in flames at the bottom of a cliff. Melissa visits Jodie in the barn, and says Luther will unlock him tomorrow. When Jodie guesses that Lucinda must have also killed the nearby farmer, she acknowledges the truth, adding that she is the only one Lucinda will listen to. That evening, after Jodie is freed, he joins the family for dinner and returns to his room. He later dreams about a crowd with torches and pitchforks, shouting, “Burn the witch.” As the mob approaches a house, Melissa and a younger Lucinda listen inside to their father, David Strickland, read the Bible. Outside, on the porch, Mr. Keitel recites the ills going on in the village and says Strickland’s daughter, Lucinda, has put a hex on them, so they have come for her. After killing the resistant father, they carry Lucinda into a field, tie her to a stake, and set a bonfire. Melissa hears a feminine voice that identifies itself as “Gorgo and Mormo,” a “friend and companion of the night,” who offers to save her sister if Melissa accepts the speaker as her new master. Melissa agrees. As she holds up her fist, the fire flickers out, leaving Lucinda disfigured but alive. Melissa hexes the villagers, sending them running. Jodie awakens, slips out of the Strickland house, and goes to Melissa’s shed to tell her about his dream. She tells him the spirit of Gorgo and Mormo——the devil—is inside him now, too, but she can only be freed if he believes the devil exists. To prove herself, Melissa displays documents proving that she is 127 years old, and the old crone, Lucinda, is her younger sister. Jodie declares he loves her despite the curse. Suddenly, Lucinda rushes into the shed and tries to kill Jodie, but when she sets the shed on fire, she is burned alive, as Jodie and Melissa escape. The next morning, Jodie tells Luther and Molly he will say nothing about what he has seen. He drives his Mustang west on the highway, then turns around and returns to the dirt road that leads to the pond. Finding Melissa, he declares his love despite the devil being in her soul. As they kiss and make love, Melissa ages into an old woman. Jodie lifts his fist into the air, appeals to the devil, and accepts him as his master. Touching Melissa’s face, he brings back her youthful beauty.