Sir Arthur Conan Doyle was both a doctor and a believer in spirits, which may partly explain why his Sherlock Holmes is one of literature's most beloved detectives: Holmes always approaches his cases with the gentility and logic of a scientist, but the stories are suffused with an aura of the supernatural. Narrated by devoted assistant Dr. John H. Watson, Holmes's adventures were so addictive that fans protested the master deducer's "death" in 1893 and Doyle had to resurrect him.