Third Agents: Secret Protagonists of the Modern Imagination brings together a varied and fascinating range of contributions to explore the role of third agents in the post-Enlightenment literary imagination, including modern narratives such as film. It centres on the figure of 'the third' - conceived imaginatively as a liminal agent transgressing social, cultural and spatio-temporal boundaries, and conceptually as the vital yet often problematic element in theories of discourse that seek to operate beyond binary codes of meaning. This figure is revealed to be a 'secret protagonist' of modernity, neglected by, and eluding the scope of, existing intellectual and literary histories. Contributors to this volume are drawn from diverse theoretical backgrounds, encompassing work in dialectics, psychoanalysis and systems theory. Through their focus on literature and media, they seek to understand how those conceptions of the third relate to imaginative figurations.This volume offers the first comprehensive account of third agency in modern literature and its intellectual and imaginative pre-history. It provides an accessible combination of close readings and theoretical reflection, presenting figures who inhabit in-between territories such as the adventurer, the bastard, the priest, the angel, the adulterer, the poet and the outcast. These figures are read as protagonists in a genealogy of modernity that has not yet been written. The essays here also provide fascinating answers as to why these secret protagonists often became major figures in modern philosophy and literary theory, and give new insights into such writers as Benjamin, Barthes and Derrida.