The frightening Boris Karloff 60s thriller with Karloff as a demented doctor using torture for scientific experiments.

Relatives of a recently deceased man meet at his eerie castle for a reading of the will. They encounter a sinister piano player who turns out to be a toy maker, and his toys are imbued with murderous intentions.

Near the end of the 19th century, Prof. John Mayer and his assistant, the scientist Dr. Isabel Reed, accidentally invent a powerful ray. An alien travels to Earth to destroy the machine since it would be a threat to the universe. He initially possesses the mind of Thomas, a sex maniac and serial killer, to get close to Mayer during the demonstration of the machine to scientists and the military. Mayer's niece, Laura, meets an acquaintance of her uncle, the chemist Dr. Paul Rosten, and Mayer invites him to join the research. When Thomas gets close to Mayer, the alien also possesses his mind in order to destroy the device and his notes. Meanwhile, Thomas is not able to control his murderous impulses and attacks several women with a straight razor.