The golden age of detective fiction gave us many stellar names. Works by writers such as Agatha Christie, Gilbert Chesterton, Earl Stanley Gardner, Rex Stout helped develop and refine the detective genre. Their novels, firmly recognized as classics to this day, are still beloved by readers and set the standard of quality for later generations of authors of detective stories. A place of honor in this galaxy rightfully belongs to John Dixon Carr (1906–1977)—a virtuoso master of perfectly constructed “impossible crimes in a locked room.” The novel “The Mystery of the Mad Hatter” continues the series of books about the amateur detective Dr. Gideon Fell. The hero’s appearance is allegedly modeled on another luminary of the detective genre—Gilbert Chesterton—and, in the opinion of most of Carr’s admirers, his contribution to the history of detective fiction truly deserves respect. For example, writer Kingsley Amis, in his essay “My Favorite Detectives,” called Dr. Fell “one of three great successors to Sherlock Holmes.”