At the turn of the twentieth century in Britain, genres such as the imperial romance framed by a white, masculine gaze expressed an imperial confidence that dovetailed with the jingoistic adventurism of high empire. But as interimperial rivalries intensified and anti-imperialist movements gained momentum, the romance’s generic and formal features were unsettled by a range of modernist techniques. While this is often recognized in stories by writers such as Conrad and Kipling, this chapter traces the modernist compressions and anti-imperial connections that run through the adventure fiction of two very different authors writing between 1900 and 1945: John Buchan, an arch-imperialist and politician whose romances and spy thrillers are warped by the threat of emerging interimperial rivalries; and Edward John Thompson, a friend of Gandhi and translator of Tagore whose Indian novels combine the generic residues of the romance with the growing presence of anti-imperial insurgencies. Drawing out these formal compressions with reference to modernist writers such as E. M. Forster, the chapter shows how adventure fictions unraveled through the empire’s final decades.