The Dracula and Frankenstein series were Hammer's two most widely loved and successful entries into their horror genre. Not only did the two classic characters jump start Hammer's change in direction from suspense to horror but they were also the two series with the most entries. Personally I haven't been a big fan of either, while in terms of production and acting I've been quite impressed, in terms of the story each preceding chapter seems to simply be a reshuffling of locations and an only slight tweaking to the main premise of the story.
Peter Cushing returns as Baron Frankenstein, in prison and awaiting the guillotine for the murders of two people at the hands of his monstrous creation. At the final hour he is rescued by a crippled guard named Karl, who releases him under the condition that Frankenstein creates for him a new body. Frankenstein and Karl move to Carlsbruck, where Frankenstein practices medicine under the name Dr. Stein. During the day he caters to the wealthy to help finance his secret laboratory, on the evenings he volunteers to care for the poor where he also obtains the needed limbs and other organs to create a new body for Karl.
Dr. Stein quickly becomes the most popular doctor in town, stealing away large portions of the other doctor's patients. This and the fact that Dr. Stein refuses to join their Medical Council does not make them a fan of his. One doctor by the name of Hans Kleve recognizes Dr. Stein as Baron Frankenstein, he agrees to keep quiet if Dr. Stein allows him to participate in his current research. Everything seems to go successfully with transplanting Karl's brain into a new body, until Hans foolishly reveals to Karl that he's going to be the wonder of the medical world and that everyone will want to study him. Obviously this was not what Karl signed up for, and things begin to spiral out of control as Karl begins to reject the plans Hans and Dr. Stein have in mind for him, a move which leads to the revelation of Dr. Stein's true identity.
With The Revenge of Frankenstein Hammer attempted to insert a little subtle humor into the film considering The Curse of Frankenstein was quite grim in it's appearance. The film is regarded as one of screen writers Jimmy Sangster's best works as he managed to take the series in a completely different direction (an opinon I would tend to disagree with). While The Revenge of Frankenstein doesn't model the novel like the original film, the basic premise of the film is pretty much the same, simply a different setting and different group of characters. But the film was a solid success in both the UK and the States, and even briefly spawned a television series pilot entitled Tales of Frankenstein, which never got off the ground. While I can't rave about the "brilliance" of the film as others may, I can say The Revenge of Frankenstein succeeds in being a relatively well crafted horror film in most regards, only truly faulting in a story that simply doesn't stand out as being that different compared to the original.