Hammer’s unique story mash up between Burke and Hare cases, legendary serial killer Jack the Ripper, and Robert Louis Stevenson’s Dr. Jekyll and Mr. Hyde is a mesmorizing gender-bender thriller.

Set in infamous Whitechapel at the height of Jack the Ripper’s murderous spree, Dr. Henry Jekyll (Ralph Bates) hell-bent on his quest for immortality, crosses moral barriers with his experiments.

At first, the young doctor pays a local mortician to acquire body parts of newly-deceased women who end up in the morgue, but when supplies run low, the doctor enlists the grisly services of two lowly gentleman, Burke and Hare, who indiscriminately kill unsuspecting victims and bring their dead bodies to Dr. Jekyll.

But Dr. Jekyll’s serum has unintended consequences, when it transforms his own body into the body of a beautiful woman, who he eventually names Mrs. Hyde (Martine Beswick). He tells his noisy neighbors, including his admirer Susan (Susan Brodrick), that the alluring woman now living with him is his recently widowed sister.

Between The Ripper and Burke and Hare, the city of Whitechapel is gripped by fear. Someone eventually finds out about deadly duo’s murderous deeds and they succomb to the town’s pitchfork. This leaves Dr. Jekyll at a disadvantage, just as he was making progress with his serum.

Sister Hyde quickly realizes her demise is tied to Dr. Jekyll’s  research, so she begins stalking the dark alleys of Whitechapel herself for young female victims to murder in the name of science.

Back in 1971, the idea of a man transforming into a woman was really taboo stuff. For some moviegoers, that in of itself was the horror. Despite the obvious misogynistic horror trope of making every other woman who appears on a screen a victim, this film really pioneered LGBTQ and woman empowerment themes.

Martine Beswick really stands out here with her cutthroat and sensual performance as Sister Hyde. She’s one spooky bitch, and probably deserves a little more attention in the pantheon of horror villains. If you’re new to Hammer Horror, definitely give this wickedly smart thriller a watch.