The Valley of Fear
The Valley of Fear is a Sherlock Holmes novel written by Sir Arthur Conan Doyle. It is the fourth and last novel in the Sherlock Holmes series (the rest of the series would be short stories). Relatively based on James McParland, a Pinkerton detective, the story originally appeared, between 1914 and 1915, in the Strand Magazin. First copyrighted as a book in 1914, it was published in New York by George H. Doran Company illustrated by Arthur I. Keller.
At the beginning of the story, Fred Porlock, a member of Professor Moriarty's gang, sends Sherlock Holmes a cipher. Porlock's original intention was to send the key to the cipher later. However, when Moriarty unexpectedly shows up, Porlock, thinking that Moriarty suspects him, tells Holmes that he has decided to not go further in the matter. Nevertheless, Holmes and Watson figure out the cipher, which tells about a certain John Douglass in danger of his life. At that point, a certain Scotland yard Policeman, Inspector Alec MacDonald, shows up. He tells Holmes that John Douglass has been murdered, and Holmes tells him about the cipher. They then go to Birlstone Manor.