In foggy London Dr Jekyll experiments on newly deceased women determined to discover an elixir for immortal life. Success enables his spectacular transformation into the beautiful but psychotic Sister Hyde who stalks the dark alleys of Whitechapel for young, innocent, female victims, ensuring continuation of the bloodstained research. With each transformation Sister Hyde becomes the more dominant personality, determined to eventually suppress the frail, ineffectual Dr Jekyll forever.

The Avengers is a British television series created in the 1960s. It initially focused on Dr. David Keel and his assistant John Steed. Hendry left after the first series and Steed became the main character, partnered with a succession of assistants. His most famous assistants were intelligent, stylish and assertive women: Cathy Gale, Emma Peel and Tara King. Later episodes increasingly incorporated elements of science fiction and fantasy, parody and British eccentricity.