This essay reads Mohamedou Ould Slahi’s Guantánamo Diary (2015) as an exemplary occasion to stage the dilemmas of postcolonial reading in the present, especially in relation to the global War on Terror declared by the United States after the 9/11 attacks. Reading Guantánamo Diary in relation to a genre it clearly seems to echo—the African American slave narrative—the essay argues that the analogy to slavery enables a deeper sense of the multiple and overlapping histories of race and empire but also obscures the transnational geography of detention signaled by Slahi as well as his damning comment on the failed project of postcolonial sovereignty. Showing how attention to questions of genre and their circulation across the globe illuminates the politics of terror and detention, the essay elaborates the possible ethics and aesthetics of postcolonial reading in the present.