JEKYLL takes place entirely in one night, during a dinner party celebrating the engagement of Henry Jekyll (Udo Kier) and Fanny Osbourne (Borowczyk regular Marina Pierro, also seen in Jean Rollin’s LIVING DEAD GIRL). A heavy-handed philosophical debate between the eccentric Dr. Jekyll and a fellow doctor (Eurotrash staple Howard Vernon) occurs at the dinner table, and when the guests retire following the meal, the mysterious Mr. Hyde shows up and upsets the household with a spree of rape, sodomy and murder — sporting a giant penis as his weapon of choice. Fanny receives a note from her betrothed advising her to keep away from him until he contacts her, but she hides in the lab and witnesses Jekyll’s transformation into the diabolical Mr. Hyde, by means of bathing in a tub of red liquid. To his shock and surprise, she leaps into the bath, immersing herself in the mutative potion so that she can join him in his unbridled mania.
One of the neglected auteurs of the European fantastic, Walerian Borowczyk was known for his bizarre erotic tales that depicted women as creatures with an all-consuming sexuality, the most well-known of which include IMMORAL TALES (1974) and THE BEAST (1975). By the time JEKYLL was released, Borowczyk had been all but dismissed by serious critics as a pornographer, even though by his own standards, JEKYLL is comparatively tame in that regard. It is also the closest he came to making an outright horror film. The movie belongs to Jekyll and his well-endowed alter ego, but the previously unassuming Miss Osbourne surprises us all in the last act with her dip into Jekyll’s bath — knowing full well what the result will be. The two set off on a massacre in the bourgeois household, dripping wet, manic, insatiable. Pierro so aptly captures the unsullied naïveté of her character that her metamorphosis seems that much more savage and violent. Most of Borowczyk’s films are concerned with social and sexual repression (and its inevitable undoing), but the combination of that cabalistic ethereality of earlier films like BLANCHE (1972) and LES JEUX DES ANGES (1965) with the accessibility of Robert Louis Stevenson’s horror classic places Borowczyk’s JEKYLL in a class of its own.
— Kier-La Janisse