Unlike other Peter Cushing outings, in which he garners star-billing, he is undoubtedly the "star" of this picture. Here he plays a absent-minded professor who finds the skeletal remains of a giant man/ape creature and brings them home to his lab in England. Although he is on the verge of occupational success, his personal life is slipping. Determined to win a prestigious science award for his discovery, he fails to give ample time to his daughter Penelope (Lorna Heilbron) who wants to know more about the mother she has never known.
Cushing isn't alone in this picture; he gets support from fellow horror icon Christopher Lee. Lee plays Cushing's half brother who operates an asylum--the very asylum Cushing had his whore of a wife sent to when Penelope was just a child. Lee serves as a nemesis for Cushing because he is seeking to win the same science award Cushing is with his research on electroshock therapy. The two men use science as a method of explaining the perverse things they do, culminating, for Cushing, in injecting Lorna Heilbron with an experimental serum he has concocted in order to keep her from the nuthouse. But the serum has the reverse effect: it speeds up her route to wearing strait-jackets.
This is a wonderful horror film, the likes of which aren't made anymore, as the genre has descended into revolting displays of gore that test an audience's gag reflex. This is story and character driven--not blood and guts driven--with Cushing carrying the piece. Both horror icons, Cushing and Lee, are in splendid form and Lorna Heilbron, as the female lead, is equal to the task of sharing the screen with them. She does a marvelous job as Penelope, beginning the film as a meek do-as-your-told daughter before transforming into a depraved nutcase that dances in the courtyard in her nighty to the music that only plays in her head.
There are enough Darwin principles and theories used in this film to sustain interest of science aficionados. Even with all the science talk, this is a quite a splendid film. Keep in mind, this is nothing like modern horror films. The monster has a fifteen minute screen time and the lone "gore scene" is tepid at best when Lorna Heilbron slits the throat of a sailor trying to rape her.