Strange Case of Dr. Jekyll and Mr. Hyde is a Gothic novella that tells the story of a London lawyer, Gabriel John Utterson, who investigates the mysterious events connected with his longtime friend, Dr. Henry Jekyll, and the sinister Edward Hyde. The impact of the work proved so profound that the phrase “Jekyll and Hyde” entered the English language as a set expression, referring to individuals of a dual nature: at times exceptionally kind, and at other times shockingly malevolent.