Joe Mulholland, Head of Production at a Hollywood studio, makes a rather fool-hardy promise to a dying friend. He undertakes to make a major movie using the title - if not the content - of a best-selling sex manual "Love in Sex". Enlisting the help of depressed screenwriter Herb Derman and rather off-centre director Sid Spokane to try and come up with an idea or two, Joe soon wishes he was not one of those people who always try to keep their promises.

Upon realizing that something truly evil haunts his home, Steve Freeling calls in a team of parapsychologists to help before it's too late.