Rosemarys Baby's ending helps to solidify it as one of the greatest horror movies of all time and leaves things on a chilling final note. Based on the novel by Ira Levin, Rosemary's Baby stars Mia Farrow as aspiring mother Rosemary Woodhouse who moves into an old Renaissance Revival-style apartment building in New York City called the Bramford with her gaslighting husband, Guy (John Cassavetes). After becoming pregnant, Rosemary grows suspicious of her neighbors and believes they have malicious intentions for her unborn baby, causing her to fight to regain control as everyone tells her it's all in her head.

Up until the horror movie's iconic ending, Rosemary seems like she could just be imagining the spooky goings-on at the Bramford her theories are so far-fetched that it would make sense to debunk them. It's more likely her imagination is running wild than the truth that her apartment complex is full of high-society Satanists.