Doug, an awkward young man who is very close to his mother, is on the verge of marrying his stunning fiancée, Callista. However, he starts to observe some unsettling changes in her behavior. He finds her sneaking out at night and being dishonest with him, and she starts showing signs of illness similar to the flu. Doug assumes she has contracted a disease from being unfaithful. In truth, Callista has been possessed by an ancient stone, leading her to secretly consume his friends and family.