The Sign of the Four is one of Sir Arthur Conan Doyle's Sherlock Holmes mystery stories. It was the second book to be published and one of the four full-length novels. In the story, Sherlock Holmes and the smitten Dr John Watson try to defeat a peg-legged man and his dwarf assistant while hunting for a fabled treasure. It was originally serialised in Lippincott's Monthly Magazine as The Sign of the Four, but collected in a single volume under the title The Sign of Four.