"A Study in Scarlet" is a novel written by Sir Arthur Conan Doyle and first published in 1887. It is the first novel to feature the iconic detective character Sherlock Holmes and his loyal friend and chronicler, Dr. John Watson. The story begins with Dr. Watson, a recently returned army doctor, looking for affordable lodgings in London. He meets Sherlock Holmes, a brilliant but eccentric detective, and they decide to share a flat at 221B Baker Street. The two men soon become embroiled in a complex murder case involving a mysterious message written in blood, which leads them to the dangerous world of revenge and conspiracy. The novel alternates between the present-day investigation and a backstory set in the American West, where the motivations for the crime are revealed. "A Study in Scarlet" is a classic of detective fiction and the first of four novels and fifty-six short stories featuring Sherlock Holmes and Dr. Watson. It introduced readers to the deductive reasoning and keen observational skills that would become synonymous with the Sherlock Holmes character.