A Study in Scarlet is a detective mystery novel written by Sir Arthur Conan Doyle, introducing his new characters, "consulting detective" Sherlock Holmes and his friend and chronicler, Dr. John Watson, who later became two of the most famous characters in literature. The story begins when Dr. Watson, having returned to London from Afghanistan, runs into an old friend, Stamford, who had been a dresser under him at St. Bartholomew's Hospital. Watson confides in Stamford that, due to a shoulder injury that he sustained in the Anglo-Afghan War at the Battle of Maiwand, he has been forced to leave the armed services and is now looking for a place to live. Stamford mentions that an acquaintance of his, Sherlock Holmes, is looking for someone to split the rent at a flat at 221B Baker Street, but he cautions Watson about Holmes's eccentricities.