A biker gang visits a monastery where they encounter black-robed monks engaged in worshipping Satan. When the monks try to persuade one of the female bikers, Helen, to become a satanic sacrifice the bikers smash up the monastery and leave. The monks have the last laugh, though, as Helen, as a result of the satanic rituals, is now possessed and at night changes into a werewolf, with dire results for the biker gang.

Sixties couples Michael and Donna and Paul and Erica become involved with the intense Count Yorga at a Los Angeles séance, the Count having latterly been involved with Erica's just-dead mother. After taking the Count home, Paul and Erica are waylayed, and next day a listless Erica is diagnosed by their doctor as having lost a lot of blood. When she is later found feasting on the family cat the doctor becomes convinced vampirism is at work, and that its focus is Count Yorga and his large isolated house.

Grace is a troubled young lady with some serious daddy issues. She was adopted as a young girl and raised up in a family of traveling faith healers. After the patriarch of that little group passes away Grace's world is thrown into turmoil. The eldest brother turns his back on the family business in favor of medical school despite being engaged to Grace and she is left alone with the shady younger son who puts Grace in a skimpy leotard and incorporates some circus style showmanship to draw in the rubes.