When aging medical hypnotist Dr. Marcus Monserrat and his wife Estelle decide they want to live beyond their years by mentally controlling the body of a younger specimen, they embroil twenty-something Mike Roscoe into their plans. But things start to go array when Estelles experiments take on a more murderous tone. Featuring horror legend Boris Karloff; and Ian Ogilvy (Witchfinder General), this second feature from critically acclaimed director Michael Reeves serves up a strange science fiction scare-fest, guaranteed to send creeps down the spine.