On the eve of a deadly blizzard, Elena Vance, a wealthy orphan, receives a terrifying warning from her mirror reflection: never open the door for her psychologist boyfriend Nathan Hale. Manipulative and obsessed, Nathan plots with his accomplices to seize her trust fund by framing her as mentally unstable.
Elena foils their first siege with wit and police help. After getting imprisoned for his crime, Nathan gets released early and abducts Elena for cruel revenge. With the help of her loyal lawyer fiancé John and the police, Elena escapes and takes down Nathan. However, a final twist reveals a shocking truth: all the mirror’s warnings are just hallucinations from Elena’s dissociative identity disorder.
