This article explores the circulation of the idea of multiple worlds as it unfolds within the creative universe of F.M. Dostoevsky. The relevance of the study lies in the interpretive complexity of The Dream of a Ridiculous Man, particularly in the insufficiently examined ontological foundations of its fantastic narrative. The piece aims to identify the mechanisms through which the possibility of a multiverse is articulated, as well as to analyze the motif of the “appearance of a star” (the imaginary Sirius) as a marker of interworld transition and as an indicator of the protagonist’s existential choice within the text. For the first time, an attempt is made to interpret the story’s cosmological utopia through the lens of non-Euclidean metrics and to reveal a connection between the image of the star in the narrative and the representation of Sirius in the “imaginary geometry” of Nikolai Lobachevsky. The study investigates how an existentially intensified problem, the leveling, or “nullification”, of sin, is articulated through the narrative framework of a “journey to another planet”. Textual parallels can be traced that connect the story with the corpus of Western European Enlightenment works (Voltaire, Flammarion), as well as with Dostoevsky’s own writings from the 1870s-1880s. The article demonstrates that the author’s hypothesis concerning the possibility of the manifestation of “other worlds” and the redemption of sin is conceptually aligned with contemporary theories of geometric infinity, the idea of the heat death of the universe, speculative models of reality construction (including non-Euclidean axiomatics), and the internal logic governing the formation of “moral feeling”, understood as being determined by the affirmation of the probability of a posthumous existence.