Sarah Moss’s novel The Fell (2021) is a fictional reflection upon the second UK lockdown in 2020 during the COVID-19 pandemic. Due to its topicality, the novel is likely to be read as a “time capsule,” preserving the unprecedented experience of social isolation, anxiety and domestic incarceration. Starting with the assumption that living in a time of pestilence may be characterised as a borderline experience, this article argues that The Fell revolves around the paradigm of liminality. For the characters portrayed in the book the threshold is social, psychological and existential. Nevertheless, for the main protagonist the metaphorical and the literal merge when, driven to the limit of endurance, she falls off the edge of a cliff while taking a walk on the fells of the Peak District, in defiance of the quarantine restrictions. The article analyses various meanings of liminality in Moss’s novel.