Jekyll and Sister Hyde" subverts the traditional story based on the Robert Louis Stevenson novel, placing it in a Jack the Ripper-era London and with a gender-bending twist in which Dr. Jekyll, experimenting with an elixir of everlasting life, brings out a female alter ego whom he identifies as his sister, Mrs. Hyde; the two alternating personalities go on a vicious killing spree through London's foggy streets, while the neighbors as well as a blind street peddler become enmeshed in the carnage.
Going into this film, I had the expectation of a pulpy, psychedelic, freewheeling seventies take on the Dr. Jekyll story (the title and posters of the film do lend to this), and was pleasantly surprised when I got a well-written and somewhat classy re-imagining. What's perhaps most intriguing about the film is that it draws on a confluence of history and fiction, incorporating the Jack the Ripper and Burke & Hare murders as a sort of inspiration for the subplot that underpins the Jekyll story; thrown into the mix is the fact that Mr. Hyde in this case is actually a Mrs. Hyde. While this conglomeration might sound silly, it actually works rather well, without ever becoming too much of a novelty for novelty's sake.
For a PG film, it is also surprisingly brutal, featuring several fairly graphic knife slashings and impalements. Thematically, there is the psychological battle between Dr. and Sister, vying for their body, and the unique gender dynamic between the two gives both Ralph Bates and Martine Beswick plenty to play off of, and they do it remarkably well. Beswick in particular is a scene stealer as the seductive and dangerous Sister Hyde. There is fantastic cinematography capturing foggy Victorian era London, as well as some inventive imagery utilizing mirrors and stained glass to illustrate the shifting personae. It very much feels like a Hammer film in terms of the aesthetic, and that lends it additional charm.
Overall, I was very surprised by this film; I expected something zany and perhaps even LSD-esque, and it was anything but. . Jekyll and Sister Hyde" takes historical events, fiction, and gender dynamics, and blends them into an English Victorian world which sets the stage for an ensuing battle between siblings as well as a Gothic exhibition of streetwalker slashings. Great, fun performances from Bates and Beswick up the ante even more.
Review by Robert_Lovelace from the Internet Movie Database.