قصة الكتاب :
A Study in Scarlet is an 1887 detective novel written by Arthur Conan Doyle . The story marks the first appearance of Sherlock Holmes and Dr. Watson, who would become the most famous detective duo in popular fiction . The story, and its main characters, attracted little public interest when it first appeared . A Study in Scarlet was the first work of detective fiction to incorporate the magnifying glass as an investigative tool . In this story a murder in London has its origins with the Mormons of America .