Mary Montgomery, the young girl who was taken by Bloody Mary in Who's at the Door?, is now 21 years old and a psychology prodigy. What awaits Mary may not be what she expects.
Alex Anderson, Dr. Paul Yang's assistant, tidies up the house in which Mary Montgomery will be staying. As her boyfriend Mike installs a new video doorbell for the house, Alex hears a terrifying voice from the past.
Dr. Paul Yang grows increasingly concerned because he has not heard from his assistant in over a week. He goes to the guest house only to find something shocking.
Before she heads back to Columbus, Mary confronts Ross about her disappearance at age 13. When she boards the airplane, Mary encounters a familiar stranger.
