Based on a series of Canadian murders and the urban legend of calls coming to a babysitter from within the house (also see When a Stranger Calls), Bob Clark and A. Roy Moore created what many feel is one of the precursors to the slasher film genre.

Bedford is a small college town, complete with a sorority house filled with victims, err, characters. While they’re celebrating at a holiday party, Jess (Olivia Hussey, who was told by her psychic to do this movie) gets a phone call from “The Moaner,” a crank caller who has been bothering the other sisters: Barb (Margot Kidder, Sisters), Phyllis (Andrea Martin, SCTV) and Clare (Lynne Griffin, Strange Brew). Barb is a real firecracker, provoking the caller, who tells the girls that he will kill them all.

Clare goes upstairs to pack and is suffocated by plastic wrap by an unseen killer and placed on a rocking chair in the attic.

The next day, Clare’s dad comes to take her back home for Christmas. The girls and their housemother, Mrs. MacHenry (Marian Waldman, Phobia), are surprised, as they thought she already went home. While all that is going on, Jess tells her boyfriend Peter (Keir Dullea, 2001: A Space Odyssey) that she is getting an abortion. He argues with her but can’t change her mind.

Meanwhile, the police get involved after learning that another girl, Janice, has gone missing. Jess also tells Chris (Arthur Hindle, Porky’s), Clare’s boyfriend, that something is up.

While everyone else joins police lieutenant Fuller (John Saxon!) to search for the missing girls, Mrs. Mac is killed inside the house. Sadly, her life of hiding booze and yelling at everyone was cut short. As the girls return home, they find Jess’ body and get another obscene call, which she reports to the police, who decide to bug the line so they can trace the calls. Then, Peter sneaks into the house for another argument.

Black Christmas is unafraid of using holiday traditions to allow its killer to get away with murder. While carolers sing outside, Barb’s screams go unheard as she is stabbed to death by a glass unicorn.

Another phone call happens — one that quotes the argument Jess had with Peter. And while that’s occurring, Phyl goes to check on Barb and is killed.

Finally, Jess keeps the obscene caller on the line long enough for a trace, which reveals that the calls are coming from inside the house. She goes upstairs, armed with a fireplace poker, to get the rest of the girls, only to find their dead bodies. The killer chases her into the cellar and when Peter appears outside the window, she assumes that he is the killer and murders him with the poker.

The police arrive to find Jess sitting with Peter’s dead body. They’re convinced that he is the killer, although they can’t find Clare or Mrs. Mac’s bodies. After she is sedated, the cops leave while one officer remains behind to wait for forensics. Then, we hear a voice whisper, “Agnes, it’s me, Billy.” Jess’ phone rings, which means her fate — and who the killer is — will remain a mystery.

One of the most frightening parts of the film are the obscene phone calls, which were performed by Clark and actor Nick Mancuso (Under Siege), who stood on his head while recording to make his voice sound more insane. Mancuso would come back to record a “Billy Commentary” on the film, which is on the recent Scream Factory! release.

Warner Brother studio executives hated the ending and demanding that Clark change the final scene to have Chris appear before Jess and say, “Agnes, don’t tell them what we did” before murdering her. However, Clark stuck to his guns and kept the ending that he believed in. The studio further tinkered with the film, calling it Silent Night, Evil Night in its original release.

When NBC aired the film as Stranger in the House on the January 28, 1978 edition of Saturday Night at the Movies, it gave stations the option of airing Doc Savage, as the Ted Bundy murders had just occurred two weeks earlier.

There’s an urban legend that this was Elvis’ favorite horror movie. It definitely made an impression on Steve Martin, who told Olivia Hussey “Oh my God, Olivia, you were in one of my all-time favorite films” when she was being considered for Roxanne. She thought he meant Romeo and Juliet, but he told her that he meant Black Christmas, claiming that he had seen the film 27 times.

There’s another urban legend — how many can one film have — that says that Halloween was originally intended as a sequel to this movie.

Clark would go on to direct Porky’s and a film that failed at first before becoming a holiday tradition, 1983’s A Christmas Story. Yep — he pretty much made both the happiest and darkest films about the Yuletide, which is pretty awesome.

I love this movie. It’s a true classic that’s unafraid to go against conventions even as it creates them. Nearly every actor and actress in this movie went on to do more and play their roles perfectly here.

You can watch it on Shudder or grab the Scream Factory collectors edition blu-ray!

While we often feature dark films here, Becca and I love Clark’s other holiday film, too. Here’s some proof, as we toured Ralphie’s house in Cleveland, OH.

The decoder ring was there and yes, the soap had teeth marks in it.