The fourth and final Sherlock Holmes novel, The Valley of Fear by Arthur Conan Doyle, takes readers on a thrilling ride filled with mystery, murder, and intrigue. When a cipher message from a pseudonymous agent of Professor Moriarty warns Holmes of a plot against a country gentleman residing at Birlstone House, little did he know that a murder had already taken place. As Holmes, Inspector MacDonald, and Watson investigate the murder, they uncover secrets, hidden agendas, and a shadowy secret society that threatens to destroy all in its path. With its focus on "problems of ethical ambiguity" and its commentary on contemporary political situations, The Valley of Fear is a masterpiece of detective fiction that will leave readers guessing until the very end.