First of all, the tagline and the claim in the trailer that you will actually see a man transform into a woman before your very eyes isn't exactly true. A man does change into a woman in this film; but the change doesn't take place 'before your very eyes'. That being said; this is still a great horror film. Hammer studios have done some great variations on classic tales, and this one stands up as one of their best. The story follows Dr Jekyll, a scientist that, when trying to find cures to every disease going realises that his efforts to prolong life will, ironically, be beaten by death. This then leads to him trying to 'beat' death with the use of chemicals, but somewhere along the way, as his experiments are oestrogen based, he ends up turning himself into a woman. Oops!
As you might expect, this isn't an entirely serious horror film. However, there are more than enough moments of horror: the scenes where Dr Jekyll and Sister Hyde battle for 'control' of their body is a brilliant piece of psychological horror, and the parts where Sister Hyde goes out to kill women in order to get more oestrogen are gratuitously bloody and should delight any horror fan. The film is also very atmospheric; the scenes on the streets are filled with smoke and are very gloomy in the way that they are filmed, which makes for a delicious setting. The cast is also brilliant; Ralph Bates is sublime as Dr Jekyll; he creates just the right mood for his character and is very believable, particularly during the split personality scenes. Martine Beswick, whom you might remember as the Bond girl in "From Russia With Love" is both sexy and sadistic as the evil Sister Hyde. She is the stand out of the movie for me. And most other men. Also in the cast is the lovely Susan Broderick, and the competent Lewis Fiander as brother and sister duo; Howard and Susan, who make for an interesting sub-plot when they both fall for Dr Jekyll. If you haven't realized already; Dr Jekyll and Sister Hyde is a great horror film, and therefore comes with the highest recommendation that I can muster.
