The Queen of Mystery has come to Harper Collins! Agatha Christie, the acknowledged mistress of suspense—creator of indomitable sleuth Miss Marple, meticulous Belgian detective Hercule Poirot, and so many other unforgettable characters—brings her entire oeuvre of ingenious whodunits, locked room mysteries, and perplexing puzzles to Harper Paperbacks. In her classic The Big Four, the great Poirot is caught up in a deadly game of international intrigue as he races to uncover the strange mystery of “Number Four.”