Strange Case of Dr Jekyll and Mr Hyde is a novella written by Scottish author Robert Louis Stevenson and published in 1886. London lawyer John Gabriel Utterson decides to investigate the appearance of the brutish and evil Edward Hyde, which leads him back to his old friend, Dr Henry Jekyll.
The files on which Watson based his later, more elaborate accounts of Holmes' investigations. They take the form of a scrapbook containing letters, sketches, newspaper articles and other documents sometimes mentioned in the more familiar forms of these stories.