In this paper, I read Terry Westby-Nunn's The Sea of Wise Insects as an example of the literary mode identified increasingly by scholars as South African postcolonial Gothic. In line with existing research, I work from a definition of the gothic genre which casts it as highly culturally specific and shaped by the anxieties of the society in which it arises. In Westby-Nunn's narrative these fears are enmeshed in the South African past, and revolve, more specifically, around the extent to which history's bearing on the present has become a dangerous point of repression. My argument traces a transgenerational logic of traumatic transmission, which situates the unspoken crimes of an old generation at the psychic nerve-centre of Westby-Nunn's contemporary protagonist, a strategy which disrupts any illusion of a stable boundary between the injustice of ‘then’ and the liberation of ‘now’. Finally, I suggest that through the deployment of an aesthetic which draws on the gothic sub-genre of horror-writing, Westby-Nunn develops a narrative which, to paraphrase Tabish Khair, does not operate “only in words”. Instead, the text relies in part on visceral reader reactions so that the novel admits of silence in a way that avoids replicating the exclusionary logic underpinning the institutionalised discrimination in South Africa's history.