Scottish author (1859–1930) whose stories featuring fictional detective Sherlock Holmes revolutionized the genre of crime fiction. Holmes himself would eventually earn a place among the most familiar and durable characters in the annals of English literature, and his exploits would inspire countless incarnations on stage and screen. ALS signed “A. Conan Doyle,” one page, 5.25 x 6.75, Ambassador Hotel, New York letterhead, April 18, 1922. Doyle writes to Mrs. Harman in New York City. In full: “I could have helped you in London but conditions are strange here. Perhaps Mrs. Cogswell of the Plaza Hotel would tell you how to approach Mr. Ticknor who is very competent, but hardly a professional….” Accompanied by the original mailing envelope, a printed announcement for Doyle’s books on psychic matters, and a 1922 leaflet on spiritualism by Lady Conan Doyle, titled “An Open Letter to a Mourner.” Intersecting mailing folds, a hint of mild soiling, and subtle brush to two words of text, otherwise fine condition. R&R COA.