The Strange Case of Dr. Jekyll and Mr. Hyde is a novel of fantasy literature written by the Scottish author Robert Louis Stevenson, first published in 1886 in London. The book was based on a nightmare that the author had, and became one of his most famous works. Dr. Jekyll is tormented by the awareness of his contradictory nature, where the tendency for good and its opposite, evil, coexist as separate personalities and compete with each other; that is why he tries to separate them through his research. He discovers the drug he created in his laboratory, which absorbs his bad side into a new personality called Mr. Hyde. However, the separation has side effects that the inventor of the drug had not predicted.

Mr. Hyde gradually becomes more and more independent. Harsh, cruel, and depressing, he commits incredibly horrific crimes, until Dr. Jekyll actually becomes his prisoner. Facing his existential anguish, the moments when he regains his sanity, he quickly realizes that there is only one way to stop the personality of Mr. Hyde.