Black Christmas: The Night Billy Came Home is a Black Christmas (1974) sequel, based in a world of reality where the sorority of Phi Kappa Sigma is being stalked and preyed upon an unknown killer.

A group of eight sorority sisters consisting of Scarlet, Natalie, Melissa, Julie, Zoe, Lily, Romy, Katherine and their fraternity neighbor Andy along with their house mother, find themselves being harassed by threatening and intimidating mysterious phone-calls during Christmas Eve and as one of the girls go missing, they each begin being murdered one by one by their house former inhabitants.—ItsMeBilly