This article presents a cognitive-linguistic study of the phenomenon of conceptual metaphor, considered as a fundamental mechanism linking two conceptual domains. The work differentiates between conceptual metaphor, rooted in the everyday conceptual system, and poetic metaphor, functioning as an individual figurative device in artistic text. The main subject of analysis is the conceptualization of the lexeme “secret” in the Russian linguistic picture of the world and in the idiolect of Ivan Turgenev. The methodology includes a comparative analysis of representations of the concept of “mystery” in languages of different families, which allows us to identify both universal cognitive patterns and ethnocultural specifics.  Based on the material from I. S. Turgenev's cycle “Mysterious Tales,” a number of individual authorial conceptual metaphors have been identified in which the abstract concept of ‘mystery’ is animated and represented through concrete images. It is argued that in the writer's later works, these metaphors perform not only a communicative but also a cognitive function, forming the semantic core of the text and conveying the idea of mystery as an uncontrollable and destructive force that determines the fate and mental state of the characters.