The Sign of Four was the second novel featuring which famous fictional detective, following A Study In Scarlet?
Arthur Conan Doyle Sir Arthur Ignatius Conan Doyle KStJ, DL (22 May 1859 – 7 July 1930) was a British writer best known for his detective fiction featuring the character Sherlock Holmes. Originally a physician, in 1887 he published "A Study in Scarlet", the first of four novels about Holmes and Dr. Watson. In addition, Doyle wrote over fifty short stories featuring the famous detective.
The Final Problem "The Final Problem" is a short story by British writer Arthur Conan Doyle featuring his detective character Sherlock Holmes. It was first published in "Strand Magazine" under the title "The Adventure of the Final Problem" in December 1893. It appears in book form as part of the collection "The Memoirs of Sherlock Holmes". Conan Doyle later ranked "The Final Problem" fourth on his personal list of the twelve best Holmes stories.