Thick fog is swirling through the streets of London, and Sherlock Holmes is lying in a cocaine-induced haze—until the sudden arrival of Mary Morstan, a distraught (and beautiful) young lady, forces the great detective into action.

 A Sign of Four is one of the most widely read adventure stories ever written. Sir Arthur Conan Doyle presents one of the most popular and studied characters in all of fiction: Sherlock Holmes, the master detective.

Published in hundreds of editions and translated into virtually every modern language, A Sign of Four has not been out of print since its initial publication in 1890.

ARTHUR CONAN DOYLE (1859-1930), one of the greatest Scottish authors, transformed the art of fiction. Author of numerous novels and short stories, including A Study in Scarlet, The Hound of the Baskervilles, The Sign of Four, and The Final Problem, he is considered to be a literary colossus, and a central figure in the development of the modern detective novel.