British estate agent Renfield travels to Transylvania to meet the mysterious Count Dracula, who is interested in leasing a castle in London. After Dracula enslaves Renfield and drives him to insanity, the pair sail to London together and Dracula, a secret vampire, begins preying on London socialites.

A countess from Transylvania seeks a psychiatrist’s help to cure her vampiric cravings.

Carpathian Count Alucard is invited to the U.S. by a young heiress. Her boyfriend and local officials are suspicious of the newcomer, who is interested in the "virile" soil of the new world.

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.