A sinister secret has been kept in the basement of an abandoned Los Angeles church for many years. With the death of a priest belonging to a mysterious sect, another priest (Pleasence) opens the door to the basement and discovers a vat containing a green liquid. The priest contacts a group of physics graduate students to investigate it. Unfortunately, they discover that the liquid contains the essence of Satan himself, and they also discover that he will release HIS father - an all-powerful Anti-God! The liquid later comes to life itself, turning some of the students into zombies as the Devil comes forward to release his father. Will these students be able to stop him?