A Study in Scarlet is Sir Arthur Conan Doyle's first novel introducing his the dective Sherlock Holmes. A Study in Scarlet refers to a speech given by Holmes to his sidekick Doctor Watson on the nature of his work, in which he describes the story's murder investigation as his "study in scarlet" "There's the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it." Sir Arthur Ignatius Conan Doyle was a Scottish physician and writer, best known for his Sherlock Holmes detective stories and for the adventures of Professor Challenger. He was a prolific writer whose works include science fiction stories, plays, romances, poetry, non-fiction and historical novels.