"In God's name, what does it mean?" "It means murder..." When Miss Mary Morstan calls on 221B Baker Street, the "utterly inexplicable" story she tells stirs the heart of Dr. John Watson - and rouses his friend Sherlock Holmes from his self-induced lethargy. For who else but London's only unofficial consulting detective could possibly solve the mystery of the disappearing Army officer, the one-legged man, his barefoot accomplice, the missing treasure-chest, and... the "sign of the four"?