In December 1893, Londoners eagerly opened their Strand magazines in anticipation of Sherlock Holmes's next adventure, only to find the unthinkable: his creator, Arthur Conan Doyle, had killed their hero. London spiralled into mourning. Crowds sported black arm bands in grief and railed against Conan Doyle as his assassin.

Then in 1901, just as abruptly as the author "murdered" Holmes in "The Final Problem,” he resurrected him. Though he kept detailed diaries of his days and work, Conan Doyle never explained this sudden change of heart. After his death, it was discovered that one of his journals from the interim period was missing, and it has never been found. Or has it?

When literary researcher Harold White is inducted into the pre-eminent Sherlock Holmes enthusiast society, The Baker Street Irregulars, he never imagines he is about to be thrust into the hunt for the holy grail of Sherlockians: the missing diary. But when the world's leading Doylean scholar is found murdered in his hotel room, it is Harold, using wisdom and methods gleaned from countless detective stories, who takes up the search, both for the diary and the killer.