Agatha Christie is known as the Queen of Crime, and for good reason. With more than 80 novels and short story collections to her name, she helped define the modern detective story, creating some of literature's most recognizable detectives and some of its most ingenious murder mysteries. While much of her work is squarely in the mystery genre, she has a handful of pieces I’d classify closer to horror. Of course, Christie's work frequently ventures into darker territory. So ma