Book excerpt: Introduction: "The germ theory again" : disease, ideology, and the possibilities of biotic life in the world of antibiotic purity -- Keep bleeding : plague, vaccination debates, and the necessity of leaky boundaries in Defoe's Journal of the plague year and Shelley's The last man -- "A speculative idea" : childbed fever, early germ theory debates, and (en)gendered speculation in Henry James's Washington Square -- Separation and suffocation : tuberculosis, etiological uncertainty, and female friendship in women's fiction -- Tainted love : venereal disease, morality, and the contagious disease acts in Ibsen's Ghosts and Hardy's The woodlanders and Jude the obscure -- Humanity's waste : typhoid fever, the failure of isolation, and the development of probiotics in three late-century works -- Conclusion: Shuffling within our mortal coil : concluding remarks.