I enjoyed this book The Sherlockian--half was told in the current day, and half followed a fictitious story about Sir Arthur Conan Doyle and his friend Bram Stoker. It's interesting, because as Star Trek has its Trekies, Holmes has its lunatic fringe groups too--and this story takes place during the annual meeting of the Sherlockian group The Baker Street Irregulars.
Then in 1901, just as abruptly as Conan Doyle had "murdered" Holmes in "The Final Problem," he resurrected him. Though the writer kept detailed diaries of his days and work, Conan Doyle never explained this sudden change of heart. After his death, one of his journals from the interim period was discovered to be missing, and in the decades since, has never been found.