Heterotopias, first conceptualised by Michel Foucault in 1966, are spaces of otherness existing outside of ordinary space, which function as counter-sites or mirrors that simultaneously reflect and contest the other spaces surrounding them. These heterotopic spaces—prisons, asylums, brothels, or cemeteries—exist in every culture, evolving over time and adapting to geographical contexts. In neo-Victorian literature, heterotopias frequently appear as spaces where history is revisited and interrogated, since it is precisely in these heterotopic emplacements where much of historical injustice took place. Accordingly, this paper proposes a reading of the Victorian sickroom as a heterotopia of deviation by examining the character of Agnes Rackham in Michel Faber’s The Crimson Petal and the White (2002). The sickroom in which Agnes is kept establishes a threshold that regulates who may enter and who may leave, allowing the husband to hide away, medically examine, and monitor the deviant Other. Control over the sickroom door, held exclusively by men, means control over female autonomy. Through Agnes, whose undiscovered brain tumour precipitates paranoid delusions, menstrual hallucinations, and religious monomania, Faber’s novel interrogates the social and medical processes complicit in constructing and containing female madness. The paper further addresses the collateral effects of Agnes’s madness on her daughter, Sophie, who is viewed by her own mother as a malevolent presence and is subsequently excluded from the sickroom. By considering the spatial aspects of madness and its construction in neo-Victorian literature, this paper argues that the sickroom, as a heterotopia of deviation, enables the maintenance of patriarchal control within the (neo-)Victorian home. Madness is thus shaped not only by medical and social discourse, but also by space, as it is managed through architecture, confinement, and the control of women’s movement.