In "The Mystery of the Spanish Chest," Hercule Poirot unravels the psychological conundrums that motivate a killer. In "The Edge," a woman must decide whether to follow her heart or her conscience. And in "The Harlequin Tea Set," Mr. Harley Quin, another of Christie's famed detectives, helps a man save his loved ones from the greedy hand of murder. Six other stories about the darker side of human nature complete the collection.