The diary of a reclusive priest named Father Carlton reveals a centuries-old secret sect in the Church called the Brotherhood of Sleep.  Carlton was on the verge of revealing their existence to the Archbishop that Brotherhood is guarding an ancient cylinder filled green fluid hidden in the basement of an abandoned 16th Century-built chapel in Los Angeles. The dormant entity inside the cylinder has been awakened by the force of a distant supernova that exploded long ago, a chaotic chain reaction disrupting order on Earth.
Another priest discovers the diary and key to the basement, encountering the cylinder and a mysterious book written in ancient languages containing mathematical and physics references. The priest contacts his former TV debate sparring partner, advanced physics professor Howard Birack, to decipher what it all means. Birack brings a research team of graduate students to investigate, who collectively experience tachyon transmissions in their dreams from the future warning about the re-emergence of an ancient evil.
The book reveals the truth: Jesus was a descendant of a human-like extraterrestrial race killed for delivering scientific warnings that no one understood. His disciples hid these warnings until such a time when science could catch up and decode the truth. The church lied publicly, telling followers that evil lies within them and could be controlled through faith.
Meanwhile, the Prince of Darkness, aka the Devil, has remained dormant in the cylinder there for two-thousand years, placed there by his father, the Anti-God. The anti-God once roamed the Earth before humankind's existence but now resides within subatomic antimatter awaiting a time for his son to reemerge to help him cross from the mirror dimension into the material world.
Something's growing in the prebiotic fluid, leaking up toward the ceiling, squirting into the mouths of the students, using psychokinetic energy to turn them evil. Satan's searching for a host to bring himself into the world to help the father escape.
John Carpenter writes and directs.