Silent Night, Bloody Night
On Christmas Eve, 1950, a man in flames runs from the house that Wilfred Butler built while a person is heard playing organ music inside. Wilfred Butler was buried on New Year's Day, and his house was left to his grandson Jeffrey Butler. The house remained empty for over 20 years, until Jeffrey finally decides to sell it.
At a hospital for the criminally insane, an inmate escapes with a wrench, runs into a parked car, and speeds away. At the same time, John Carter, a lawyer from nearby New York City, arrives at the Butler estate with his girlfriend Ingrid. Meanwhile, Diane drives by a man who is at the side of the road by a car (he is seen beating on the windshield).
John goes to see Mayor Adams (Diane's father) about buying the house and also meets newspaper publisher Charlie Towman, "communications director" Tess Howard, and Sheriff Bill Mason. Meanwhile, the unseen escaped inmate arrives at the deserted Butler house, kills a barking dog, and walks inside. Back at the mayor's office, John tells the group that Jeffrey Butler wants $50,000 in cash by the next day. Tess agrees to connect the phone line for John (who is staying at the house), and John says he has never met Jeffrey and that the man simply called and left a key for him.
John and Ingrid return to the house and, following a light dinner, head for the bedroom. Tess calls just to make sure the phone is working, and John goes to the car for cigarettes and comes back with a tiny gift for Ingrid, which he says that she cannot open yet. While the two lovers are in bed, the inmate walks in and chops them both up with an axe. The killer then telephones the sheriff, saying that John Carter is not at the house. Thinking that it might be Jeffrey calling, Sheriff Mason hangs up and the killer then calls Tess at the switchboard that it is Marianne and that the killer is waiting for her in her father's house. Tess quickly calls Maggie and tells her to come on over.
Meanwhile, the man that Diane saw on the road find's John's car with the keys in the ignition, and he drives the car to Diane's house and knocks on the door. As Diane opens the door and points a gun at him and asking who he is, the man says that he is Jeffrey Butler and shows her identification. He says that he wants to get into his house, and Diane says that the sheriff's deputy might have a key.
Tess tells Maggie that, if she has not returned from the Butler house in an hour, to call only Sheriff Mason or Towman, and no one else. The sheriff arrives at a local cemetery, and finds a diary sitting by Wilfred Butler's grave and is he immediately whacked in the face with a shovel. Meanwhile, Jeffrey returns to Diane's house and says that the deputy was not at home. Diane gets Jeffrey a drink and they talk about the house. She says that a woman keeps calling for her father and says she is waiting at the Butler house. Diane and Jeffrey drive to the Butler house together and they find the sheriff's car and his sunglasses at the cemetery. The two go see Towman, and she says that Tess has gone to the estate. Jeffrey and Towman drive to the house (leaving Diane at the newspaper office), but Towman drives to Tess' place and, finding no one around, he gets in his car and drives away, leaving Jeffrey behind.
Meanwhile, the killer calls Towman's office and after Diane says her name, asks the woman to bring her father to the house. The unseen killer says that it is Marianne, and she has a diary, referring to Christmas Eve of 1935.
Tess finds Mason's car by the house and calls out his name. She walks inside and a flashlight is shown in her face. The killer tells her not to be scared and offers her a hand... which falls to the floor. Tess screams and the killer swings his axe at her.
Diane reads old newspapers and learns about Wilfred Butler's daughter, Marianne, being attacked and raped when she was 15. In 1935, Butler gave his house to Dr. Robinson to be made into a local insane asylum where he committed his daughter. Towman has "cut out" the ending to the story.
Jeffrey returns to the office and Diane asks about his mother Marianne, whom Jeffrey was told had died in childbirth. Jeffrey reads the newspapers, and Diane suggests that his mother is alive and waiting at the house. As they drive to the house, they find Towman's car in flames. Further down the road, Jeffrey accidentally swipes Towman with the car. Jeffrey stops and sees that the man is dead, and he tells Diane that someone had cut off Towman's hands. A little later, they finally arrive at the house, and see Mason's car. The killer calls Mayor Adams and tells him about the "reunion" at the house and says that his daughter will be there. Adams picks up a shotgun and heads out.
At the Butler house, Jeffrey finds a diary and reads of Marianne's child being taken away and sent to California. Doctors and guests lived in the house, and Wilfred was upset about the way the people acted. One day, as the doctors drank and danced, Wilfred went to Marianne's room where he admits to being the father of her baby and leads her away. To save the patients from being "abused" further by the doctors, Wilfred had freed the inmates. The crowd of lunatics walked into the house as a Christmas Eve dinner was being held and savagely murdered the doctors at the dinner table. As Wilfred went to the car, Marianne has slipped away, and the inmates, believing she was a doctor, killed her.
Diane walks into the house and Jeffrey tells her that Wilfred is still alive, making the town believe he was dead by setting fire to a squatter he found at the house. Jeffrey also says that the sheriff, Tess, Towman, and Diane's father were all former inmates at the asylum and they had in fact founded the town while Wilfred had apparently been residing in an another asylum all these years. Mayor Adams arrives at the house and finds a dead body on the porch and screams. Diane gives Jeffery her gun. As Mayor Adams walks inside, the two men shoot each other. At the top of the stairs, the killer, whom is finally revealed to be an 80-year-old Wilfred Butler, appears, telling Diane (whom he addresses as "Marianne") not to run away. A flashback shows a young Marianne running from her father. Diane goes to Jeffrey's side, grabs the gun, and shoots Wilfred three times, who tumbles down the stairs. Diane runs into a room and cries, leaving the house at daybreak.
In the final shot, set another year later, the Butler house is seen being torn down.
