One of the best Frankenstein films
We all know the basic Frankenstein tragedy: A brilliant scientist is obsessed with creating life and eventually succeeds, but his creation goes on a killing spree, although the creature is nice to kids 'cause they're innocent. Ultimately the monster must be destroyed (and the creator usually goes with him).
I like how "Frankenstein Must Be Destroyed" deviates from Shelley's overdone plot. The story involves Baron Frankenstein as a fugitive going by a different name yet still intent on continuing his gruesome work. He cunningly manipulates a young couple into assisting him wherein they apprehend a patient from the local asylum to conduct experimental surgeries.
This is one of the best Frankenstein flicks I've seen. It's creative, labyrinthian and full of pizazz. Being a sequel, the film retains the essential elements of the original story but is a natural progression. The REAL monster in this picture is Baron Frankenstein himself; he's no longer a basically decent, brilliant person obsessed with creating life. His obsession has defiled him to the point of enmity, hate, arrogance, violence, rape and murder.
Speaking of the brief rape sequence, I always felt it was forced into the script to make the series more 'cutting edge' at the height of the counterculture movement (1969). In other words, it was out of character for Baron Frankenstein but producers didn't care because they wanted to keep the series 'hip' and profitable in the late 60s. That said, I suppose it can be defended on the grounds that Victor got morally worse as the series proceeded and his arrogance increased; and this was the second to last film (discounting “The Horror of Frankenstein” which was a redo of the original story with a different actor).
The film is highlighted by Veronica Carlson, who looks a lot like Ursula Andress, but possibly even more beautiful (if you can imagine that).