Arthur Conan Doyle was a Scottish writer and physician best known for his stories featuring the legendary detective Sherlock Holmes. Conan Doyle was a prolific author and his innovative mysteries make him one of the most widely read authors in history. Conan Doyle also wrote The Lost World, which was one of the earliest and most influential works in the lost world genre of fiction. A Study in Scarlet, published in 1887, is the first novel featuring Sherlock Holmes and Dr. Watson. The book centers around a murder mystery after a dead man is discovered in a room in Brixton. The Sign of the Four, published in 1890, is the second Sherlock Holmes novel. The book begins with a beautiful young woman asking Sherlock and Watson to accompany her as she meets with a mysterious benefactor. The Hound of the Baskervilles, published in 1902, is the third Sherlock Holmes novel. The book centers around an attempted murder that was inspired by the legend of a diabolical supernatural hound. The Valley of Fear, published in 1915, is the fourth and final Sherlock Holmes novel. The book begins with Sherlock receiving a message from an agent of Professor Moriarty.