By the late 1840s, a new genre of literature revealed deep concerns with corruption in the growing urban centers. City mysteries exposed a dark underworld of the metropolis, leading readers through smoky saloons, gambling dens, and brothels. More than any other “sin of the city,” urban gothic literature focused on prostitution. The female prostitute embodied the greatest antithesis to the ideal or “true” woman. Anticonvent literature often compared nuns to prostitutes, convents to brothels, priests to seducers, and Mother Superiors to madams. City mysteries mirrored convent narratives in their description of women being seduced into lives of misery and sexual deviance. Both convent narratives and city mysteries promised to unveil a hidden world of sin and debauchery for an eager readership. This chapter compares convent tales and city mysteries, focusing on the nun-prostitute figure and the ways in which this female archetype threatened nineteenth-century female gender norms.