The Memoirs of Sherlock Holmes

By the time Sir Arthur Conan Doyle had completed the twelve stories for The Strand magazine that are gathered together in The Adventures of Sherlock Holmes, he was already growing tired of his most famous creation, but the financial incentive to continue was too great.
So began the second series of stories, known as The Memoirs; these introduced such notable characters as Holmes' indolent brother, Mycroft, and Holmes' most dangerous adversary, Professor James Moriarty, the 'Napoleon of Crime'. The collection included such stories as 'The Adventure of the Resident Patient' and 'The Adventure of the Greek Interpreter', which Doyle would list later as amongst his favourites.
It was to Moriarty that was delegated the task of ending the career of the world's finest consulting detective in a final, fatal encounter at The Reichenbach Falls in Switzerland in the concluding tale, 'The Final Problem'.