Former child actor Johnny Downs earns top billing in this low-budget horror film, which also stars George Zucco as Dr. Lorenzo Cameron, a mad doctor who has discovered a way to turn his helper, Pietro (Strange), into a wolf man. The lycanthropic experiments succeed, and although Dr. Cameron spouts plans of turning his discovery into a weapon in defense of the civilized world, he instead unleashes his creation on those fellow scientists who had engineered his ouster from academia.