"四签名：沟通桥梁与决策之道"相对平均偏差怎么算

　　When she receives pearls beyond price and a mysterious message from an anonymous source, Miss Mary Morstan goes to the famous consulting detective of 221B Baker St., Mr. Sherlock Holmes for advice in how to answer the message. Together with his staunch comrade, Dr. John Watson, and a mutt named Toby, Holmes tracks down the secret of the Sign of Four.