The book "The Mystery of the Six Napoleons" by Arthur Conan Doyle

The author of the stories about the private detective Sherlock Holmes is the English writer Sir Arthur Conan Doyle. The character of Holmes is one of the most vivid literary characters, so much so that many believed him to be real. According to a survey, on average, every fifth Briton believes that Holmes really existed, and in London there is even his "house-museum", where the flow of fans never dries up. Even during Conan Doyle's life, other authors wrote stories about the detective's adventures. Conan Doyle's son Adrian, a number of outstanding authors wrote about Holmes: John Dickson Carr, Ellery Queen, Maurice LeBlanc, Stephen King, Rex Stout, Mark Twain, Boris Akunin and even US President Franklin Roosevelt.