This article explores the convergence, inversion, and collapse of heterotopic spaces in E. S. Thomson’s neo-Victorian Jem Flockhart series about a cross-dressing female apothecary in mid-nineteenth-century London. The eponymous first-person narrator becomes embroiled in the detection of horrific murder cases, with the action traversing a wide range of Michel Foucault’s exemplary Other spaces, including hospitals, graveyards, brothels, prisons, asylums, and colonies, with the series substituting the garden for Foucault’s ship as the paradigmatic heterotopia. These myriad juxtaposed sites, which facilitate divergence from societal norms while seemingly sequestering forms of alterity and resistance, repeatedly merge into one another in Thomson’s novels, destabilising distinct kinds of heterotopias and heterotopic functions. Jem’s doubled queerness as a cross-dressing lesbian beloved by their Watsonean side-kick, the junior architect William Quartermain, complicates the protagonist’s role in helping readers negotiate the re-imagined Victorian metropolis and its unequal power structures. Simultaneously defending/reaffirming and contesting/subverting the status quo, Jem’s body itself becomes a microcosmic heterotopia, problematising the elision of agency in Foucault’s conceptualisation of the term. The proliferation of heterotopias in Thomson’s series suggests that neo-Victorian fiction reconfigures the nineteenth century into a vast network of confining, contested, and liberating Other spaces.