Boris Karloff meets Bela Lugosi for the first time in this highly-stylized and bizarre horror film that has a devil-worshipping architect, a hateful scientist and an innocent married couple. The scientist meets the couple aboard a Budapest-bound train. The trio end up on the same bus. When it crashes, the mysterious Dr. Vitus Verdegast (Lugosi) invites the newlyweds to take shelter at the mountain-top home of architect Hjalmar Pocizig (Karloff) who greets them dressed in an inky black robe. The couple are also frightened by his black lips and his bizarre haircut. Unbeknownst to the lovers, Verdegast has come for vengeance, for it was Pocizig who caused the deaths of thousands of Verdegast's countrymen during the war. It does not help that Pocizig commemorated the event by building his house upon the grisly site. During the war, the doctor was incarcerated and while serving his time, Pocizig stole Verdegast's wife and then married her daughter after she died. Not wanting to lose the stolen wife forever, Pocizig keeps her corpse perfectly preserved under glass. He does not tell Verdegast that he has married the daughter. As carefully constructed as Pocizig's black world is, it is not flawless and with some help from the newlywed husband, things quickly become unraveled, allowing good to once again triumph over evil.