In London, Dr. Henry Jekyll, a kind and respected physician deeply invested in the duality of man, believes that within every individual lie two separate personalities: one good and one evil. Driven by a desire to free humanity from its darker side, Jekyll develops a chemical potion intended to isolate and eliminate human beings' evil qualities. Despite warnings from his friends and his fiancée, Muriel Carew, about the dangers of his experiments, Jekyll's obsession with his theories leads him to test the potion on himself. The experiment yields terrifying results, transforming him into Mr. Hyde, a violent and ruthless embodiment of his inner darkness, unleashing his suppressed desires without moral restraint.

As Hyde, he roams the London streets at night, indulging in debauchery and swiftly becoming entangled in a life of hedonism and violence. His encounters with Ivy Pearson, a bar singer who becomes tragically involved with Hyde, highlight the stark contrast between his two identities. The Jekyll persona struggles to control and understand his transformations, seeking a way to reverse the effects of his experiment. Meanwhile, his professional reputation and personal relationships, particularly with Muriel, begin to suffer as the consequences of his dual life become increasingly difficult to conceal, setting the stage for a profound conflict between his public persona and the hidden, monstrous side of himself.