The film opens on a young woman running from a monster. A very, very slow monster. There is literally no way the creature can catch up to her as it meanders. There is only one thing she can do. Stop and scream until it catches her. Not a good start.
Thankfully, this turns out to be an early example of the “they are actually shooting a movie” trope. Unfortunately, the film they are making is the same caliber as Frankensteins 1970. Why 1970? For the same reason Dracula 3000 is called Dracula 3000, to sound futuristic. Movies with dates in the titles are a pet peeve of mine and I judge them harshly (see Amityville 1992).
Presumably, the film takes place in the far future year of 1970. A future where Victor von Frankenstein, a descendant of Richard von Frankenstein, who we know as Victor von Frankenstein, is the last of the Frankensteins and is using up the last bits of the family money to follow in Richard’s (Victor’s) footsteps.
For that he needs more money, a rambling dramatic monologue, and a … nuclear reactor. That’s why the wanted to be set in the far future of 12 years from then, because it wasn’t thought plausible that a normal guy like Frankenstein could get a nuclear reactor in 1958, but 1970, now that’s a different story.
Also, the makers of the films don’t know what a nuclear reactor is.
By renting his castle to the movie producers, he gets more money. By acting in the movie, he gets the dramatic monologue and somehow, he got the reactor.
Boris Karloff portrays Frankenstein in his fifth Frankenstein film, however, this is the first time he plays the mad scientist himself. He gets a little meatier backstory than the character usually gets in these films. He is disfigured and scarred, both physically and mentally, after being tortured by the Nazis. He didn’t play ball with them. He might be a mad scientist but he ain’t no fucking Nazi.
Karloff is the only reason to watch the film. He carries it on his shoulders to the extent that there are long segments of the film where it’s just him walking about, looking at things, turning knobs, etc. It’s Victor von Frankenstein’s world, the rest of the characters are just dying in it.