Doyle wrote a novel The Land of Mist centered on spiritualist themes and featuring the character Professor Challenger. He also wrote many non-fiction spiritualist works. Perhaps his most famous of these was The Coming of the Fairies (1922),[88] in which Doyle described his beliefs about the nature and existence of fairies and spirits, reproduced the five Cottingley Fairies photographs, asserted that those who suspected them being faked were wrong, and expressed his conviction that they were authentic.