One night, a female demon attacks Rick, a contentedly married man. Under the spell of the demon, he takes a beautiful young woman, Ariel, off to an isolated house for a weekend fling. There, bizarre and frightening things happen, and accidentally Rick kills Ariel. But she won't stay dead. He soon realizes that she is the demon that first attacked him. When he finally escapes and returns home, he discovers that his life has disappeared into a nightmare of madness, lust, adultery, and cold-blooded murder.