The Valley of Fear by Author Conan Doyle

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The Valley of Fear is the fourth and final Sherlock Holmes novel by Sir Arthur Conan Doyle. The novel starts with Sherlock Holmes receiving a cipher message from Fred Porlock, a pseudonymous agent of Professor Moriarty. After Porlock sends the message, however, he changes his mind for fear of Moriarty’s discovering that he is a traitor. He decides not to send the key to the cipher, but he sends Holmes a note telling of this decision. From the cipher message and the second note, Holmes is able to deduce that it is a book cipher and that the book used for the encryption is a common book, large (with at least 534 pages), printed in two columns per page, and standardized…