This is the very first film adaptation of Curt Siodmak's science-fiction novel DONOVAN'S BRAIN. The movie was made by Republic Pictures and released in 1944. Siodmak was not involved in the production, which was directed by Western veteran George Sherman.
In a spooky castle-like building (which is called...."The Castle") somewhere in Arizona, a determined man named Professor Mueller (Erich von Stroheim) is experimenting with ways to keep a brain alive and functioning after the death of its body. Luckily for Mueller, a small plane crashes in the area, and he sends his assistant Dr. Patrick Cory (Richard Arlen) to help any survivors. Only one man is still alive, and Cory takes him back to the castle. With the man near death, Mueller takes the opportunity to remove his brain and keep it going. At first Cory is against the procedure, but he soon becomes as obsessed as Mueller in keeping the brain alive. The brain actually belongs to a notorious tycoon named William Donovan, and it soon starts to communicate and take control of Cory. Cory's girlfriend Janice (Vera Hruba Ralston), who is also assisting Mueller, wants the experiment to end, but Mueller refuses. Things come to a head when Cory regains control of himself.
THE LADY AND THE MONSTER is a title that has very little to do with the plot of the film. It was probably used as a way to give the film a more Gothic flavor, as was the casting of Erich von Stroheim and the use of a dreary castle as the main setting. Professor Mueller's laboratory inside the castle wouldn't be out of place in a Universal chiller, and he has a elderly housekeeper who keeps snooping around. Cinematographer John Alton gets plenty of chances to indulge in some atmospheric black & white photography, and he also uses harsh lightning on Richard Arlen's face when he is being "possessed" by Donovan's brain.
The Gothic elements do not mix too well with the second half of the film, where Arlen travels to Los Angeles to engage in some financial misdeeds under the control of the brain. These scenes take place in brightly lit, spacious offices, and Arlen, while under the brain's influence, acts as surly as possible. (I much prefer Lew Ayers' more nuanced performance of the Cory character in the 1953 adaptation of the story, DONOVAN'S BRAIN.) At nearly 90 minutes, the story tends to drag a bit when von Stroheim and the castle location is not involved.
The Lady of the title is played by Vera Hruba Ralston, a Czech ice-skater who was being groomed by Republic head Herbert Yates to become a movie star--mainly because she had a personal relationship with Yates. Ralston is certainly attractive, but she's not the most expressive performer in the world. There's a suggestion that Mueller has designs on her, but this never goes anywhere. Ralston not only gets top billing, she gets billed before the title! One wonders what someone like Evelyn Ankers could have done with the role.
The best thing about THE LADY AND THE MONSTER is Erich von Stroheim, who gives Mueller a limp and a personality that seems more from the 1800s than the mid-20th Century. The scenes of Mueller and his castle don't quite mix with the sequences of Arlen in the modern world dealing with lawyers and bankers. The movie also has a narration that feels contrived, and a climax that could have been handled much better. I still believe that the best film version of this story is the 1953 DONOVAN'S BRAIN.