Reginald Le Borg was a banker in Austria and a director in America, making low budget horror at Universal like The Mummy’s Ghost and Weird Woman. Released along with The Creeping Unknown, it was ahead of the Shock Theater package that would ignite a new interest in Universal’s horror movies. It’s also Bela Lugosi’s last movie, although footage of him appears in  Plan 9 from Outer Space.

Dr. Gordon Ramsay (Herbert Rudley) claims that he is innocent yet remains in jail, guilty of murder, when surgeon Sir Joel Cadman (Basil Rathbone) offers him a chance at redemption. All he has to do is assist him with some experiments, starting with taking a potion called The Black Sleep, which will put him into a deathlike slumber.

After the “dead” body of Ramsay is discovered in his cell, Cadman takes the body for burial and revives Ramsay back in his lab. There, he’s attempting to learn the mysteries of the brain so that he can bring his wife Angelina (Louanna Gardner) back to life. One of his servants, Mungo (Lon Chaney Jr.) was once Doctor Monroe, one of Ramsay’s former teachers. Now he’s a monstrous beast barely under control. And then there’s the mute — and frightening — Casimir (Bela Lugosi).

So why do Laurie (Patricia Blake), Odo (Akim Tamiroff, who replaced Peter Lorre, who wanted more than this production could pay for) and Daphnae (Phyllis Stanley) work for him? It turns out that Laurie is Mungo’s daughter and wants her father to be normal again. That said, there’s an entire basement filled with experiments that haven’t worked, broken human beings — like Tor Johnson — led by a maniacal preacher named Borg (John Carradine). They’re so close to breaking through the doors to the lab…

The Black Sleep has a great cast but doesn’t do much with them. But it’s a fast movie and if you don’t think too much — or want to hear Bela speak — you may enjoy it.

You can watch this on Tubi.