Mystery fiction has long been regarded a conservative genre that focuses on crime, surveillance, and the restoration of disrupted social order. Such assessments, however, usually consider only a very small subset of works. We find a very different story if we consider the mysteries of modern life more widely, starting with the international, penny-press phenomenon of the mid-nineteenth century city-mysteries narrative. Expanding and historicizing the genre in this way reveals diverse variants of popular mystery that emerged out of the city mysteries – up to and including the detective story – and that constitute an extraordinarily wide-ranging and socially radical genre. The paradoxical attitudes towards visual powers and problems at the heart of the modern mystery cultivates a form of master-perception concerned more with identification with than identification of and models forms of empathetic vision that work to challenge the very social hierarchies the genre has often been understood to uphold.