Dr. Jekyll and Mr. Hyde' is a novel written by Robert Louis Stevenson in 1886. The story follows the dual personality of Dr. Henry Jekyll, a kind and intelligent man who experiments with chemicals to unlock the darker side of his personality, Mr. Edward Hyde. The two characters represent the duality of human nature, with Jekyll representing the good side and Hyde representing the evil side. The novel explores the idea that everyone has both good and evil within themselves, and the struggle between the two sides.