 the 1950s), the storyline follows an amnesiac man who, after being injected with "irradiated wolf serum" by unscrupulous doctors, transforms into a werewolf when under emotional stress.The film "marks precisely the point in which horror, which had been a dormant genre in the early '50s, began to take over from science fiction", and is the first of only three werewolf films made in the US during that decade, preceding "Daughter of Dr. Jekyll" and "I Was a Teenage Werewolf" (both 1957).