1970 film directed by Roy Ward Baker
Dr. Jekyll and Sister Hyde is a 1971 UK film based on the short story Strange Case of Dr Jekyll and Mr Hyde by Robert Louis Stevenson. The film was made by British studio Hammer Film Productions and was their second adaptation of the story after their 1960 film The Two Faces of Dr. Jekyll.
While searching for an elixir of life, Dr. Henry Jekyll begins using female hormones taken from fresh cadavers supplied by Burke and Hare. These have the effect of not only altering his character (for the worse) but also of changing his sex, transforming him into a gorgeous but evil woman. To explain the sudden appearance of his female half around the house, he calls himself Mrs. Hyde, saying she is Jekyll's widowed sister. Dr. Jekyll soon falls in love with Susan Spencer, the upstairs tenant, but Sister Hyde develops a lust for her brother. Jekyll soon finds that his serum requires a regular supply of female hormones to maintain its effect, necessitating the killing of young girls. Dr. Jekyll abhors this, but Sister Hyde relishes the killings as she begins to take control, even killing Jekyll's friend Professor Robertson when he attempts to question Hyde about the murders. As the two personalities begin to struggle for dominance, Jekyll only just managing to thwart Hyde's attempt to kill Susan. He then commits one last murder to find a way to stabilize his condition, but he is interrupted by the police after a comment by the now-blind Hare leads them to realize the similarity between Jekyll's earlier experiments on cadavers and the Ripper murders. As Jekyll tries to escape by climbing along the outside of a building, he transforms into Sister Hyde, who, lacking his strength, falls to the ground, dying as a twisted amalgamation of male and female.