The article deals with the analysis of one of the most mysterious images in American literature of the 19th and 20th centuries, that is Number Forty-four from two manuscripts by Mark Twain ("Schoolhouse Hill", 1898; "No. 44. The Mysterious Stranger", 1902-1908). The purpose of the article is to determine the genesis of Forty-Four. The relevance of the study is determined by the unresolved issues related to the history of the character's creation: over the past fifty years, researchers of Mark Twain's works have tried to find out why the writer chose a number as a name for his protagonist (No. 44 series 864, 962) and what the function of this number was. Particular attention is paid to the role of Mark Twain's personal contacts in creating the story of Forty-four: his friendships with N. Tesla, J. Szczepanik, and T. Leschetizky. The author of the article supports American literary critic Louis J. Budd's hypothesis of the possible influence of Adam Mickiewicz (the poem "Dziady") on M. Twain and puts forward his own hypothesis about the influence of the works of Nikola Tesla, Matthias Villiers de L'Isle-Adam (his novel "New Eve") and science fiction writers of the 1890s, who created adventure novels about Thomas Edison ("edisonades"), androids, time travel and aliens. Though Mark Twain did not dare to publish his manuscripts about Forty-four for ethical reasons, he became a pioneer in science fiction in the light of this new hypothesis. Twain proposed a fundamentally new story about an alien - not a hostile one, but the one who wants to be friends with the citizens of the Earth and help them. In addition, Mark Twain is the first to write about an android from another planet. The novelty of the research is seen in the fact that for the first time a comprehensive approach to solving the "riddle of Number Forty-four" is proposed: it is based on both the facts from Twain's biography and the wide historical and cultural contexts of his era.
