His Last Bow (with linked TOC‪)‬

The most significant thing about Doyle's London was that it was inhabited by Sherlock Holmes and Doctor Watson, who seem more real to us than most historical figures. They've managed to convince any number of people of their reality. Presumably the British post office no longer receives letters address to Sherlock Holmes from all over the world, but once upon a time, it received thousands. Collected her are eight Sherlock Holmes adventures.