"The Black Sleep" is an interesting if not particularly entertaining mix of high and low horror elements.
It's got Sherlock Holmes himself, Basil Rathbone, in the leading role as a high-minded scientist, spouting dialogue in his signature clipped British accent. Classy Hollywood character actor galore John Carradine is here, too. And it's got the generally higher production values associated with an "A" picture, released as the top half of a double bill with "The Creeping Unknown."
But the story is a derivative Dr. Moreau knockoff, complete with a late-arriving menagerie of twisted creatures to terrify the distressed damsel. The other lead, the idealistic younger doctor recruited as the assistant, is a mortal stiff.
Perhaps its most intriguing aspect is the inclusion of several famous "creature feature" actors, now running out the string as their careers wind down: Lon Chaney Jr., Ed Wood favorite Tor Johnson. And it's got ol' Dracula himself, Bela Lugosi, in his final film role. Sadly, he plays a mute and doesn't actually speak any lines; his lips quiver with the effort of communication, as if frustrated by his lack of dialogue.
(Lugosi's "appearance" in Wood's (in)famous "Plan 9 from Outer Space" three years later actually consisted of test footage shot outside of his home shortly before his death in 1956.)
This is one of those old-school horror films that has several genuinely chilling moments, but they're interrupted by long dialogue scenes where the characters explain quite obvious expository information to each other.
"You mean that shambling madman used to be the brilliant Doctor Monroe! How could that be?!? Oh, yes, that huge scar on his skull, and the fact we're in the castle of a famous but maniacal brain surgeon, may have something to do with it."
Things start off well enough, with some narration about the mysterious drug "nind adhera" from the furthest reaches of India, also known as "the Black Sleep" for its ability to put people into a death-like slumber -- from which they can be conveniently awoken with the proper antidote.
It seems Dr. Gordon Ramsay (Herbert Rudley) is to be hung from the gallows for murdering a moneylender named Curry. On the night before his execution, Sir Joel Cadman (Rathbone), a former instructor of his, comes to offer his condolences and slip a mickey of the black sleep into Ramsay's drink, telling him it's a sedative that will ease his death.
Ramsay is astonished to wake up two days later in his own coffin, with Cadman and his obsequious gypsy toady, Udu (Akim Tamiroff), leering over him. In return for saving his life, Cadman requires Ramsay to assist him in his dark experiments upon the human brain.
The science of the film is pretty goof even for its day, with Cadman attempting to map the functional areas of the brain one at a time by performing surgery on perfectly healthy specimens obtained via Udu. They've all been failures, leaving the patients with serious disabilities or deformities. Cadman is tuning up his skills so he can remove a brain tumor from his suspiciously young and beautiful wife, who now resides in a (normal) coma.
Ramsay goes along for awhile, until it becomes obvious that Cadman is just using humans as guinea pigs for experiments. He joins forces with pretty assistant Laurie (Patricia Blake), who is later revealed to be the daughter of one of the early surgical failures, Mungo (Chaney), an oafish strongman who goes into a murderous rage whenever he sees his daughter.
Phyllis Stanley has a neat, underwritten role as Daphnae, Cadman's nurse and right-hand woman, who appears to harbor a secret, unrequited affection for him. I was hoping this would build up into a full-throated love triangle, with the devoted servant ultimately betraying her undeserving romantic object, but it was not to be.
Johnson turns up almost at the very end as Curry, Ramsay's supposed murder victim, still very much alive if blind. Carradine plays Bohemund, an apparent amnesiac who fancies himself a Holy Crusader who encourages deadly vengeance against the Saracens, his famous stentorian voice booming through Cadman's dungeons.
Sally Yarnell plays an unnamed female patient who's left with a head that's half-bald and a body covered in patchy fur. (I guess it was the hair-growing part of her brain that got trashed.) George Sawaya plays a handsome young man who gets turned into a gargoyle.
I'm not sure how audiences in 1956 took "The Black Sleep." It seems pretty silly and contrived now, prime material for a "Mystery Science Theater 3000" type of spoof. Merely watching it for what it is, or at least what it wants to be, seems a gross experiment.