What makes this book a classic is Christie's knack for showing just how human crime can be. This novel is a timeless tale, and yet so characteristic of the period it was written in. The parallels between Christie's fiction and the reality of the Lindbergh baby tragedy give us a glimpse of what people must have been thinking as the true crime unfolded. Who could murder a child in cold blood? How could anyone let that sort of monster walk free? When is justice at the hands of the everyman valid? Can revenge ever be the humane choice? Few novels leave me feeling intellectually stimulated, but this is certainly one. The narrative is simple and straight forward enough, but this is a book you only need read once a lifetime and yet always come back to.