Collections of novels and other series written by Sir Arthur Conan Doyle. Cover image: 1) Sir Nigel illustration by Arthur Twidle for The Strand Magazine (june 1906) 2) The Crime of the Brigadier illustration by Sidney Paget for The Strand Magazine (december 1899) 3) Le Capitaine Sharkey, Le Petit Parisien (june 1908) 4) Conan Doyle disguised as Professor Challenger for The Strand Magazine (april 1912)