Dementia 13 (1963), written and directed by Francis Ford Coppola.
The family gathers at a gloomy Irish castle for "let's make Mother write us into the Will" shenanigans. The brothers have American wives for some reason, one of whom will go to great lengths to get what she wants. But who is that guy with an axe who pops up when least wanted, and how high can the body count go?
On the one hand this is a minor thriller with a plot that's hard to follow at times, but on the other:
Coppola's first film (age 24) has that Roger Corman fast and cheap look which really adds to the entertainment value of this sort of picture. Nightmares are sometimes barebones and minimalistic in production value.
Despite that you can still see the film student's eye and recognize his interest in making something a bit better than average.
The frantic harpsichord score is just what you want in a cheap midnight movie.
Patrick Magee fanclub!
Produced by Roger Corman, who brought in Jack Hill -- another beginning director -- to shoot additional scenes. I don't know to what extent, but would imagine they involved women doing more midnight swimming in their underwear and exploring the spooky castle in a transparent nightgown.
Available on Blu-ray from HD Cinema Classics.
The good:
They include a DVD made from the same remastering effort and you can see the Blu-ray is better.
Blacks are often inky.
The bad:
The cleanup has involved heavy denoising which smears out the fine detail and introduces larger artifacts in some scenes. It may be the worst case I have seen on Blu-ray.
Blacks are persistently crushed and whites blown out.
No English subtitles.