In which story does Sherlock Holmes reappear after 'The Final Problem'?

Sherlock Holmes reappears after “The Final Problem” in “The Adventure of the Empty House.” Arthur Conan Doyle published the story in 1903, making it the first tale set after Holmes’s supposed death at Reichenbach Falls.

The story explains that Holmes survived his struggle with Professor Moriarty and spent several years travelling while dismantling the remains of Moriarty’s criminal network. Dr. Watson, who believed Holmes dead, encounters him in disguise and is astonished to discover that his friend is alive.

Holmes’s return is tied to the murder of Ronald Adair. The killer is Colonel Sebastian Moran, a former associate of Moriarty, who uses an air gun to shoot at a wax bust of Holmes. Moran’s appearance also establishes him as one of the major villains in the later Holmes stories.

A common mix-up is “The Hound of the Baskervilles,” which was published after “The Final Problem” but is set before Holmes’s apparent death. “The Empty House” is the genuine return story and begins the collection “The Return of Sherlock Holmes.”