The Return of Sherlock Holmes, by Sir Arthur Conan Doyle

Holmes is alive! Poor Watson gets a shock when Sherlock Holmes walks back into his room and into his life. Moriarty may no longer be part of the criminal scene in London, but there is plenty of puzzles to solve, nonetheless.
audio: 11 hours (audiobook available from Librivox.org)
text: 318 page (eBook available from Project Gutenberg)