Four people are hired to stay in a haunted house for a week to determine whether or not ghosts are inhabiting the place. Franklin is a medium who believes she is able to communicate with the spirit world, McDowall is a physical medium who has stayed in the house before, and Revill is a skeptical physicist who brings along his wife, Hunnicutt. The man who is paying for their stay is eccentric millionaire Culver. As it turns out, the joint is being haunted by the ghost of a long-dead decadent millionaire (Gough, in an unbilled, silent cameo) who indulged in all manner of sadistic perversions while alive and whose corpse now emanates evil. While director John Hough (TWINS OF EVIL) does a fine job with the things-that-go-bump-in-the-night aspects of the material, he fails to breathe any life into Richard Matheson's woefully underdeveloped screenplay, which he adapted from his own novel.