Unnatural narratives—those that subvert conventional narrative norms—have gained prominence across various media forms, yet remain analytically elusive within classical narratological frameworks. This study proposes and tests an integrated model titled the Possible Worlds–Umwelt Model, which systematically analyzes three interwoven levels of narrative: (1) narrative structure through the lens of possible worlds theory, (2) character subjectivity via five Umwelt-based dimensions (time, space, identity, causality, and sensory perception), and (3) the cognitive agency of the audience in reconstructing unstable narratives. Employing thematic analysis and semiotic coding, the study examines four representative works across media and cultural boundaries: Inception, Fight Club, Mahi va Gorbeh (Fish & Cat), and the interactive game Stanley Parable. Results indicate that the proposed model not only effectively captures non-linear and layered narrative structures, but also allows for measurable analysis of mental states and audience engagement across diverse narrative environments. By combining narratology, cognitive theory, biosemiotics, and cultural semiotics, the model offers a replicable and transferable framework applicable to film, literature, and interactive media. Moreover, it enables culturally responsive narrative analysis beyond Eurocentric paradigms, positioning itself as a viable tool for interdisciplinary and cross-cultural narrative research.