Cult/ Black Christmas (CTBA)

Before Halloween and Friday the 13th came to define the slasher movie, director Bob Clark laid the groundwork with Black Christmas - a chilling, suspenseful masterpiece that transformed an ordinary holiday into a nightmare.

As the festive break begins, the residents of a sorority house find themselves tormented by a series of obscene phone calls. But when one of the young women disappears, the disturbing messages give way to something far more sinister.

With a relentless killer hiding in plain sight and panic mounting inside the house, the survivors must confront an unseen evil before Christmas comes to a bloody end.

Steeped in atmosphere and mounting dread, this Canadian classic is a landmark of psychological terror whose shocking ingenuity and nerve-shredding suspense make it one of the most influential horror films ever made.