Opera is a genre that prizes interior expression. How then does it cope with characters who are defined by reticence and inscrutability? Donizetti's 1837 opera Roberto Devereux thematises these issues – a reflection, in part, of the nineteenth century's growing anxieties over public self-expression. Engaging with contemporary 1830s criticism, this article focuses on two numbers in the work that were identified as problematic by early audiences, arguing that their perceived failure is a consequence of the work's inventive depiction of its characters' vacant subjectivities. Donizetti's opera can be seen to stretch primo Ottocento operatic conventions to their limits, in the process undoing the traditional correspondence between interior expression and self-definition.