["The British Journal of Sociology, EarlyView. ", "\nABSTRACT\nSociological accounts of modernity have long emphasized rationalization, alienation, and the attenuation of affective intensity. While these diagnoses capture crucial dynamics of modern social order, they leave underexplored a persistent and generative dimension of social life: enchantment. Few existing attempts to theorize enchantment in modernity treat it as anything other than a residual survival at the margins of an otherwise disenchanted world; those that avoid this residualist framing often relocate enchantment outside culture altogether, grounding it in material vitality or hybrid ontologies rather than in social meaning. This article proposes a different approach by identifying mystery as a constitutive cultural structure of modern enchantment. Mystery organizes interactional encounters with the unknown by transforming a mundane absence of information into an issue of transcendent significance, generating affective tension and imaginative depth. By locating enchantment in the ordinary texture of cultural experience, mystery decentralizes enchantment, dissociating it from conceptual frameworks that concentrate enchantment in religion‐like centers. Focusing on fleeting encounters with strangers in urban settings, mediated by architectural transparency and mobility, I show how windows, glass façades, and trains structure perceptual and emotional engagements that orient modern sensibility. Drawing on literary and artistic representations—from Baudelaire and Hopper to Le Corbusier and Hitchcock—I argue that mystery is not a residual pre‐modern trace but an endogenous and durable feature of modern urban experience.\n"]