Directed by Erle C. Kenton | Starring: Lon Chaney Jr., John Carradine, Lionel Atwill, Martha O'Driscoll

A scientist working on cures for rare afflictions, such as a bone softening agent made from molds to allow him to correct the spinal deformity of his nurse, finds the physical causes of lycanthropy in wolf-man Larry Talbot and of vampirism in Count Dracula, but himself becomes afflicted with homicidal madness while exchanging blood with Dracula.