The Blancheville Monster (1963)

Alternatively known under the single word title Horror, this is a low rent knock-off of "The Fall of the House of Usher", complete with madness, mesmerism, and someone being buried alive.  And to its credit, it tries its darnedest the capture the elaborately Gothic atmosphere of Poe's original tale.  Alas, it does so at the cost of pretty much every other factor of the film.

Emily Blancheville returns home from an extended absence.  Her brother confesses to her that her father - whom he had told her was dead - in fact still lives, but is horribly disfigured, horribly mad, and intent on murdering Emily before the end of the week!

There is a prophecy, you see, that the house of Blancheville will fall when a female member of this generation reaches the age of 21, and Emily just so happens to have that important birthday fast approaching.

Now you may be wondering to yourself "Self, why didn't dad kill Emily when she was still a baby, if he believes in the prophecy?  Surely it would have been easier."  Well if you are, congratulations, because you have spotted the first of the many (many) flaws in the villain's dastardly plot to see her dead.  Though not so egregious as their inexplicable failure to actually, you know, try to kill her.  Instead they repeatedly mesmerise her and make her wander the mansion grounds.

Is this villain the slimy new family doctor?  Or is it the beautiful but strange new governess?  Well of course not.  It's transparently obvious it's the brother, because in any "drive them mad and then kill them" Gothic tale it's always the closest relative who's to blame.

Eventually brother dearest mesmerises Emily so deeply she appears to be dead, and she is buried alive.  This scene is actually quite effective.  Or would be, if they could decide whether Emily's eyes are open or not during the burial.

Fortunately, Emily manages to get out of the family sepulchre, and her brother is so surprised he falls down a well.  There, I've generously spoiled the whole thing so you don't have to waste 85 minutes of your lives watching it.  Feel free to thank me in the comments :-)