"A Study in Scarlet" is the first novel featuring Arthur Conan Doyle's famous detective character, Sherlock Holmes. The story is divided into two parts: the first part is set in London, where we are introduced to Dr. John Watson, who has just returned from military service in Afghanistan and is searching for a place to live. He is introduced to Sherlock Holmes, a consulting detective who takes on cases for clients. Together, they investigate the mysterious deaths of two men, seemingly unrelated but with a common thread: both were found with the word "RACHE" scrawled in blood on the wall. In the second part of the novel, the story shifts to Utah in the 19th century, where we learn the backstory of the murderer and the events that led up to the deaths in London. The novel is notable for its introduction of Holmes and Watson, and for its complex plot that weaves together seemingly unrelated threads.