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.
John Carradine
Count Dracula
Onslow Stevens
Dr. Franz Edelmann
Lon Chaney Jr.
Lawrence Stewart Talbot
Martha O'Driscoll
Miliza Morelle
Jane Adams
Nina
Lionel Atwill
Police Inspector Holtz
Glenn Strange
The Frankenstein Monster
Ludwig Stössel
Siegfried
