These are the last twelve stories Conan Doyle wrote about Holmes and Watson. They reflect the disillusioned world of the 1920s and also include some of the wittiest passages in the series.

Holmes' much-needed spa vacation in Cornwall is cut short when a bizarre case crops up, prompting the famed detective and his assistant Watson to get involved. Although the strange tragedy that befalls a local family is initially blamed upon the Devil himself, Holmes' clever sleuthing proves that the true perpetrator was all too human.

A novel and a collection of short stories in one book. In the Valley of Fear, the intrepid detective and his trusty partner must delve deep into the mystery of a seeming suicide at a manor. At the heart of the case is a secret organization and some truly nefarious men. In the second set of eight stories, women go mysteriously missing on a holiday, The British government comes under fire, and German spies make an appearance, among the many baffling cases tackled by the iconic duo.

His Last Bow is a collection of previously published Sherlock Holmes stories by Arthur Conan Doyle, including the titular short story, "His Last Bow. The War Service of Sherlock Holmes" (1917). The collection's first US edition adjusts the anthology's subtitle to Some Later Reminiscences of Sherlock Holmes. All editions contain a brief preface, by "John H. Watson, M.D.", that assures readers that as of the date of publication (1917), Holmes is long retired from his profession of detective but is still alive and well, albeit suffering from a touch of rheumatism.

In The Casebook, you can read the final twelve stories that Sir Arthur Conan Doyle wrote about his brilliant detective. They are perhaps the most unusual and the darkest that he penned.