The Valley of Fear Conan Doyle

Sherlock Holmes and Dr. Watson receive a letter from an informant known by the pseudonym Fred Porlock. Porlock is part of Professor Moriarty"s criminal organization. The letter is written in a numeric code, and Holmes decodes the letter, which warns that John Douglas of Birlstone House is about to be murdered. Это и многое другое вы найдете в книге The Valley of Fear (Conan Doyle)