"The Strange Case of Dr.Jekyll and Mr. Hyde" is a story by the Scottish writer Robert Louis Stevenson. The story tells the intricate and macabre story of a notary Londoner (Mr. Utterson), forced to investigate the mysterious and disturbing episodes, between his old friend (Dr. Jekyll) and the malevolent Mr. Hyde. History has had a universal impact, so much so that the definition of "Jekyll and Hyde" has actually entered into the common world language. It means, in fact, a person with two distinct personalities: one good and the other evil.