Devil Doll

Devil Doll is a 1964 British horror movie about a sinister magician and ventriloquist (Bryant Haliday) who uses his powers to gain the fortune of a wealthy heiress (Yvonne Romaine). The film also starred William Sylvester and Sandra Dorne.

Plot Summary
The Great Vorelli (Haliday) is a famous ventriloquist whose dummy Hugo can seemingly talk and act on its own. Unbeknownst to the audience, Vorelli has used black magic to trap the soul of his former assistant inside the doll, allowing it to come to life. Vorelli is also a talented hypnotist; during a show, he brings the pretty socialite Marianne Horn (Romaine) onto the stage and hypnotizes her into becoming a talented dancer. Vorelli appears to bring Marianne out of her trance, but secretly maintains a mental hold on her.

Marianne's boyfriend Mark (Sylvester) wants to do a story on Vorelli, so he asks Marianne to invite the ventriloquist to perform at her aunt's charity ball. Vorelli uses the opportunity to place Marianne further under his control, with the goal of marrying her in order to get her fortune. When his jealous assistant Magda (Dorne) threatens to expose him, he goads Hugo into killing her.

Marianne's strange behavior prompts Mark to investigate Vorelli's checkered past. In the meantime, the hypnotized Marianne professes her love for Vorelli and her intention to marry him. Vorelli tells Hugo that he's not really interested in Marianne, only her money; once he has that, he will kill her and transfer her soul into a marionette to join Hugo as part of his act. But Hugo has a secret of his own- he's been studying the same black magic. He breaks free from his cage, attacks Vorelli, and swaps their souls.