Sir Arthur Conan Doyle is better known for his detective, Sherlock Holmes, than for his stories and novels of fantasy and science fiction, but his contributions to these other genres were formidable. His enormous popularity as a result of the Sherlock Holmes stories allowed him to command a large audience for nearly anything he wrote, and those who read his fantasy and science fiction almost always were rewarded with skillfully written, entertaining, and sometimes thought-provoking tales. Most scholars of Doyle's work agree that in the Sherlock Holmes stories, he advanced plot formulas, narrative conventions, and characters inherited from writers he admired, such as Edgar Allan Poe and Émile Gaboriau, to realize a truly new and powerful literary form, what has come to be known as the classical detective story. Few would argue that his work in fantasy and science fiction advanced those genres in the same way...