Sarah Winchester is the widow of a famous gunman named William Winchester. The sudden death of her husband and her previous daughter Annie left her in severe suffering. With more than 20 million dollars inheritance from her husband’s business, Sarah becomes convinced that she is cursed by the ghosts who have died from the weapons her husband produced. After looking for advice from a medium, she begins to build an enormous villa that seems to be no longer the case, and which will be called the Winchester Mystery House.

The house is in a continuous construction, and Sarah’s relative, Marion Marriott, lives in that house with her son Henry. At night, Henry is possessed by a mysterious entity. In 1906, Winchester employs Dr. Eric Price to rate Sarah because it is considered not to be in all mental faculties and therefore incapable of dealing with the company’s leadership.

Eric laments the death of his wife, Ruby, and he’s addicted to some of the medications he gets because of his job. He comes to that house where he meets Marion. She is distant from Eric at first, and while preparing for dinner, he is shocked to see a ghost, but he thinks it’s just an adverse effect on drugs. After a tense dinner with Sarah, Marion and Henry, they return to their rooms. During the night, Eric comes out of the room and sees a ghost, and when he goes out to take some air he realizes that the place is full. Henry holds the roof of the building, and Eric saves him in the sight of Sarah and Marion.