The Case-Book of Sherlock Holmes is the final set of twelve Sherlock Holmes short stories (56 in total) by Arthur Conan Doyle first published in The Strand Magazine between October 1921 and April 1927.
The Case-Book contains three stories not narrated by Dr. Watson, as most Sherlock Holmes stories are. "The Adventure of the Mazarin Stone" is narrated in the third person, since it was adapted from a stage play in which Watson hardly appeared. "The Adventure of the Blanched Soldier" and "The Adventure of the Lion's Mane" are both narrated by Holmes himself, the latter being set after his retirement.
Although some of the stories are comparable with Doyle's earlier work, this collection is often considered a lesser entry in the Sherlock Holmes canon.