Sherlock Holmes reappears in London after a three-year absence, shocking Dr. Watson who believed his good friend had been killed in a confrontation with Professor Moriarty at Reichenbach Falls. Holmes is compelled to outwit the âsecond most dangerous man in Londonâ who has a good reason to hope for Holmesâ demise. From the 1905 collection The Return of Sherlock Holmes.