Dr. Tim Mason (Roger Pryor (actor)), a medical researcher experimenting in "frozen therapy" visits the deserted home of Dr. Leon Kravaal (Boris Karloff), the originator of the therapy, who has been missing for ten years. After discovering a secret passage in the basement, Dr. Mason and his nurse (Jo Ann Sayers) discover Kravaal and four other men frozen in a pair of hidden ice chambers. The doctor and nurse successfully revive Kravaal, who then revives the other four men. Things turn more sinister as Kravaal holds everyone captive in order to use them as guinea pigs, hoping to unlock the key to "frozen therapy."