While we are staying with the mad scientist for a bit longer, this one is a genuinely new take on the concept, namely the brain transplant. Plus Karloff and Lugosi, so that's a bonus.
We have a typical New England professor lecturing his class. Professor George Kingsley (Stanley Ridges) is your run of the mill English teacher. The students like him, the school likes him, in general he's a nice guy.
He's about to have an untypical day though, for when he crosses the street he is struck by a speeding car, being driven by gangster Red Cannon. Cannon was involved in a high speed chase, which ended with him hitting Kingsley and a brick wall. Kingsley is dying from a massive brain injury and Cannon is sure to follow.
In steps Dr. Ernest Sovac (Bois Karloff), Kingsley's best friend. He doesn't want to lose his friend, plus he has this new medical theory he wants to prove, so why kill two birds with one stone? He operates, taking parts of Cannon's brain and replacing the damaged parts of Kingsley's head. The end result-Kingsley's alive! Except now, for random bit of time, he seems to talk a lot like Cannon, and knows things only Cannon would know.
Sovac is puzzled by this, but then he reads why Cannon was driving that car in the first place. It seems he had stashed roughly half a million dollars somewhere and he refused to tell the rest of his gang. It was them who were chasing him. Sovac is concerned for his friend of course, but then again half a mill could do the world...and him, an awful lot of good. So he takes Kingsley to Cannon's old New York stomping grounds, hoping it will jog his memory.
It does, and in the worst way too. Cannon totally takes over Kingsley and uses his newly deceased status to take out his former cohorts, working his way up to the gang's new leader, Mannay (Bela Lugosi). Can Sovac control his creation and still get the money?
Pretty good and a brisk running time. It starts out with your typical mad scientist theme but then completely switches over to a gangster film so flawlessly you would think the script was the subject of a brain switch too.