This film can't really be talked about without spoilers regarding a certain infamous scene that happens about 45 minutes into the running time. However, this review contains no spoilers regarding the plot itself.
The 5th in Hammer's run of Frankenstein films starring Cushing, "Frankenstein Must be Destroyed" takes a few liberties with its central character, turning him from a vaguely amoral yet still likable enough dandy-doctor (sort of like Jon Pertwee without the gurning) into a complete bastard who it'd be impossible to like at all. And yet it still works.
Peter Cushing is the reason to watch this film. To be honest, the plot itself isn't one of the best of the series, for the most part seemingly rehashing the basic premise of the superior "Revenge of Frankenstein", with Frankenstein back to conventional brain swapping, working with a foppish aide in various cellars, and a "monster" with an identity crisis. There are several plot strands working at once and not all of them really work (a duo of police inspectors investigate proceedings for the first hour or so, decide to go and find the Baron, and then are seemingly forgotten, never appearing again), and the monster stuff seems to have been chucked in as an afterthought.
However, the development of the actual core character is far more interesting, and one doesn't really mind the plot taking a back seat. One thing that becomes increasingly clear when watching these Hammer Frankenstein films is that they do actually have clear progression for the character of Frankenstein himself, which surprised me quite a bit. From being a young, cold scientist, through to a slightly nicer, though still rather unethical, sort, and finally settling down to become nicer still, by the time of this film he's completely gone and lost his humanity. The real monster of this film is Frankenstein himself, colder, more cunning, more manipulative and nastier than ever before. He no longer smiles, he sneers. He seems to hate everybody, using people as puppets for as long as they are useful to him - compare his relationship with his assistant here to that he shared with Thorley Walters in "Created Woman". Though he's killed before, never has it seemed as off-hand and easy for him as it does here, with several stabbings and decapitations being put down to his handiwork. And then of course there's the infamous rape scene.
In the sort of scene which I would never have expected Peter Cushing to be a part of, Frankenstein spies on Anna, the girlfriend (if I remember rightly) of his unwilling assistant Karl, as she stands in her bedroom in her nightie, and then continues to walk in, lock the door, and, yes, rape her. Though the camera cuts away before the actual act itself, there's enough physical contact and such to know what the end result would have been. It's the most harrowing scene Cushing's ever had to perform, and the long stretch of time he spends just staring at Anna cranks up the tension more than any other Hammer horror has ever managed to do. Incidentally, this scene was added to the film as a complete afterthought when shooting had almost finished, as it was considered by the distributors that the film as it was didn't have enough sex in it. Quite why a rape scene was judged as an acceptable addition I don't know (rather than, say, a random spot of nudity or an appearance by a randy courting couple), but the inclusion of it, though making for uncomfortable viewing, really does advance the character of Frankenstein himself and shows how depraved he has become, and how much emotion he now lacks. Peter Cushing and Veronica Carlson understandably didn't want to do it at all. If I may nick a quote from Veronica Carlson in "The Peter Cushing Companion" -
"Peter didn't want to do it. He took me to dinner one evening to discuss it but it didn't make the scene any easier. I couldn't refuse to do it. Terence Fisher (the director) was very understanding but it was totally humiliating. Every alternative was more vulgar than the last... Terry just said 'Cut, that's it,' and turned away. Peter and I just stayed there and held on to each other."
This does explain why, after this scene, Anna doesn't seem to act any differently around Frankenstein compared to before the rape, as most subsequent scenes were filmed earlier on. I suppose the validity of the scene's inclusion depends upon each individual viewer. Ironically, the scene was cut from American prints.
Though the film is incredibly dark, there is some vague delight to be had at actor spotting. For your Doctor Who fans there's George Pravda (who appeared in three stories, best remembered as Spandrell in "The Deadly Assassin") and the chap who played Dr. Warlock from "Pyramids of Mars". Then there's also Windsor "It Ain't Half Hot Mum" Davies as a policeman, and Thorley Walters as the chief inspector with Geoffrey Bayldon as his wonderfully cynical aide. The latter partnership provides the only comedy to be had in the whole feature, and it's a shame that they have no bearing on the story at all.
There's not much more I can say about this film, really. It's a very good story, and I've left most of it for you to discover. Beware however that it's not a rosy-cheeked bit of "so bad it's good" fun, and may actually disturb and even frighten you to some extent. It should definitely be near the top of any Peter Cushing fans' list of films to see.
Review by The_Secretive_Bus from the Internet Movie Database.