Bob Clark’s 1974 horror film Black Christmas is an influential slasher movie, although the ending doesn’t reveal who the killer is in Black Christmas. “Billy” is considered the villain, and after almost 50 years, his identity is still debated. The story takes place in a sorority house, where the residents throw a Christmas party before departing. Little do they know, however, that a perverted killer has made his way into the house and is preparing to pick them off one by one. Billy remains in the shadows for most of the movie, that is, until the chilling ending.

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