This story, set in 1891, introduces Holmes' greatest opponent, the criminal mastermind Professor Moriarty. It appears in book form as part of the collection The Memoirs of Sherlock Holmes. Conan Doyle later ranked 'The Adventure of the Final Problem' fourth on his personal list of the twelve best Holmes stories. Holmes arrives at Dr. Watson's one evening in a somewhat agitated state and with barked knuckles. He has apparently escaped three murder attempts that day after a visit from Professor Moriarty, who warned him to withdraw from his pursuit of justice against him to avoid any regrettable outcome. Holmes has been tracking Moriarty and his agents for months and is on the brink of snaring them all and delivering them to the dock. Moriarty is the nexus of a highly organised and amazingly secret criminal force and Holmes will consider it the crowning achievement of his career if only he can defeat Moriarty.