A brilliant roman à clef that offers stunning portrayals of Byron, Percy Bysshe Shelley, and other members of the author's circle, Mary Shelley's The Last Man (1826) also gives an account of a devastating plague that eventually eliminates the world's population. Critics often emphasize one of these two aspects of the work, viewing it either as a construction of the author's community or as a destruction (or "deconstruction") of that community. This essay modifies both accounts by modifying our understanding of the function of the plague in the novel. Disease does not merely eliminate population in Shelley's narrative; it reconfigures the meaning of population by reconfiguring the meaning of other persons to the self. As a result, the novel does not simply represent the destruction of human communities, it also represents a shifting understanding of them. The earlier chapters of the novel, closely resembling the genre of domestic fiction, repeatedly assert the value of beliefs and genetic filiation in the formation of social groups. The later chapters, by contrast, represent the plague as an occasion to treat community more expansively in order to protect persons from harmful actions. As homes begin to look like institutions and families expand to absorb and protect more-and unrelated-members, Shelley's novel approximates the period's most innovative philosophies of liberal institutions.