At the mansion of his Great Aunt Kate, Larry Abbot is undergoing a psychological procedure designed to rid him of his irrational phobias, by frightening them right out of him! But the jolts and frights may turn out to be the least of his problems when Great Aunt Kate names him her sole heir. Suddenly, the entire family seems a little too vigorous in participating with his "scare-apy," leading Larry to believe that one of his jealous kin may be murderous, and that another may be werewolverous!