When Virginia Woolf said that human character changed ‘in or about December, 1910’ she was probably not thinking of the London Tube. Woolf appears to have taken the date from the year of the art exhibition ‘Manet and Post-Impressionism’ in her essay ‘Mr Bennett and Mrs Brown’ (1924) and it seems a far cry from the subterranean world of the London underground. In the 1930s, however, Woolf might have added that the Tube had as much of an effect on perception as Post-Impressionism but this would have been at least in part due to her own writing. Woolf's writing changed the way we think about the underground system and she was the literary inventor of the Tube after 1910, laying down a blueprint that would mark out new boundaries as a subject for writing. Her essay asserted a major shift in human relations that was based on her perception of changes in society, a view that could equally well have been applied to the writing of the new electric tubular railway. Woolf's essay suggested a move beyond fictional realism towards more expressive forms of art and the Tube offered many new possibilities. This was the literary creation of the Tube (with a capital T) even though, ironically, the earliest appearance of this abbreviation in fiction was in Arnold Bennett's short story ‘The Fire of London’ (1904), the ‘Mr Bennett’ whom she had attacked in her essay. After 1910, an unprecedented amount of artistic and literary energy went into trying to find ways to construct the Tube in writing and this chapter will explore how and why modernism engaged with the underground until the beginning of the Second World War. Whilst still firmly located within the city, modernism moved the apprehension of the urban world from its political and economic structures to what Lynne Hapgood calls a ‘geography of ideas’.