A respectable London doctor's experiments with his own personality unleash a monstrous alter ego upon the city. Dr. Henry Jekyll, a man of science and reputation, becomes obsessed with separating the good and evil within himself. His experiments lead to the creation of Mr. Hyde, a being of pure malevolence who gradually gains control. Jekyll struggles to contain Hyde, fearing the destruction of his own life and the lives of those around him as Hyde's violence escalates.

Robert Louis Stevenson's novella is a seminal work of Gothic literature, widely recognized for its exploration of the duality of human nature. The stark contrast between the respectable Dr. Jekyll and the depraved Mr. Hyde has become a cultural touchstone, frequently referenced and adapted. Critics often highlight the story's psychological depth and its commentary on Victorian repression and societal hypocrisy. The narrative structure, which gradually reveals the horrifying truth, contributes to its enduring suspense and impact.