Switcheroo

 

 (imdb)

DOCTOR JEKYLL & SISTER HYDE-1971-During the Jack the Ripper time, Dr. Henry Jekyll (Ralph Bates; in LUST FOR A VAMPIRE the same year) writes a testimonial that turns into a flashback. Jekyll is working on an anti-virus vaccine. When the pompous but crazy Prof. Robertson (Gerald Sim) says it would take too long to perfect his serum, Jekyll becomes obsessed with doing it quicker, working day and night continuously. He's experimenting with female hormones using corpses from a morgue. When he runs out of corpses, he hires Burke (Ivor Dean) & Hare (Tony Calvin) to help him. You know what that means. After some experiments with flies, Jekyll takes his own concoction and becomes a woman (Martine Beswick). She becomes Jack The Ripper in this early gender bender horror story directed by Roy Ward Baker and written by Brian Clemens for Hammer Pictures.

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