Every mystery novel challenges the reader to beat the main character in finding a solution. However, sly authors obscure enough so that pertinent details fall into place only in hindsight — after the hero sleuth saves the day. The mysteries listed below are just the opposite. Each contains everything necessary to solve the puzzle — except for the brand-name detective. When the story ends, it is the reader who must dazzle with his or her out-of-the-box thinking and deductive reasoning. Answers lie in appendices for defendants of defeat.