C. Auguste Dupin, investigator extraordinaire, was the remarkable creation of Edgar Allan Poe. Written in the 1840s, Poe presented the acutely observant, shrewd but idiosyncratic character who, with his chronicler, provided the inspiration for Doyle's more famous Sherlock Holmes and Dr Watson. Here are the three Dupin stories. What is the strange story behind The Murders in the Rue Morgue? Can Dupin solve, by analysis from afar, The Mystery of Marie Roget? And how can he possibly retrieve The Purloined Letter when the efforts of the Paris police have been in vain?