Director José Mojica Marins travels to spend Christmas with friends on their small farm and write the screenplay for his next film. But he observes eerie things in the house. His friends are being possessed one by one by some supernatural evil force. Soon he learns that the matriarch of the family had made a deal with local witch, Malvina, to get pregnant and save her marriage. In return, Malvina should indicate who would marry the girl. However, her daughter Vilma is engaged to her beloved fiancé, and Malvina wants her to marry Eugenio--the son of Satan. Further, José Mojica Marins discovers that his fictional creation Zé do Caixão (a.k.a. Coffin Joe) is ready to collect the souls of Vilma's family, and only an exorcism might save the doomed family.