What Are Those Strange Drops of Blood Doing on Jennifer's Body?

Two young women, Jennifer and Marilyn, move into a luxurious high-rise apartment, only to find themselves being stalked by a mysterious killer. As they try to uncover the identity of the stalker, they must navigate a cast of suspicious characters, including a predatory lesbian neighbor, a strange old woman and her deformed son, and the building's architect, who harbors a severe phobia of blood.