Defending himself against accusations that his 1907 novel The Secret Agent was offensively morbid, Joseph Conrad explained in an author’s note that the ‘sordid surroundings and the moral squalor of the tale’ were inspired by his impression of London as a ‘cruel’ and ‘monstrous town'. Conrad’s portrayal of the city in The Secret Agent has been extensively examined, yet one crucial aspect has been curiously overlooked: a corruption scandal engulfed the real-life governmental body in charge of clearing London’s slums and reconstructing the city in 1886, the very same year that the novel is set. Situating The Secret Agent in its historical context, this article argues that Conrad's vision of London in The Secret Agent is a reaction against a specific, idealistic vision for London promoted by the urban planners and reformers of his day. London appears as threatening in Conrad's novel because the process of urban reconstruction reveals that urbane behaviour and human self-control are, ultimately, little more than façades.