Larry Forbes (Shepperd Strudwick) travels to a tiny French village, where he crosses paths with Dr. Renault (George Zucco), his niece (Lynne Roberts) and his strange assistant, Noel (J. Carrol Naish). Forbes is intrigued by the scientist, but soon learns that under Renault's harmless façade lurks a dark secret. The doctor is linked to a recent string of murders in the town, and Noel is the product of a ghastly experiment.