Doctor Jekyll, a London doctor, is convinced that it is possible to separate good and evil within the human psyche, by means of a chemical process. One evening he experiments on himself with the potion he has developed. He is transformed into a being that he calls "Hyde".
This was the first spoken film adaptation of Stevenson's novel, and the savage, sexual side of Hyde's personality had never before been presented so violently. "I was interested in showing the relationships between Nature and Civilisation. […] Hyde was certainly not a vile individual but a savage who could not understand anything that was happening around him" (Rouben Mamoulian). As for Jekyll, he was engaged to be married, but frustrated by the constant postponement of the wedding, and Hyde is the monstrous result of this frustration that builds up in a repressive and puritanical society. Taking a very bold and innovative approach, Mamoulian's virtuoso direction is similar to the avant-garde experiments of the Twenties.