Mohamedou Ould Slahi is arguably one of the most famous contemporary Mauritanians worldwide. This is largely owed to his Guantánamo Diary, a bestseller that he penned while he was an inmate in Guantánamo prison. The memoir appeared in January of 2015, reflecting on Slahi’s plight as a wrongly incarcerated detainee in the (in)famous jail. Prosaic and sincere, the book, so far the only voice of a Guantánamo detainee, depicts the wretched life within a Kafkaesque oubliette, an impersonal, yet rationalized and inhumane, castle where legality is suspended in a state of exception. Slahi’s story is about the inside humane oscillations of a homo sacer, struggling to come to terms with his difficult situation. Ever since the book appeared, and after Slahi’s release and return to his home country of Mauritania in October 2016, Slahi’s post-Guantánamo life has attracted attention from communities of readers worldwide. This aggregate interest is now accumulating in a forthcoming Hollywood movie based on Slahi’s story. Various factors conspire to encourage this interest, much of which involves the politics of reading, imagination, and hermeneutics of the respective readers. Yet I will argue that the story should interest Africanists as well. First, Slahi’s is a Mauritanian story, telling us numerous facts about African culture and politics in the region and how they coalesce in Slahi’s story. Second, even from a theological perspective Slahi’s intellectual and personal profile reflects a story of African post-Islamism, a theology of forgiveness rarely outlined in the literature. Third, Slahi is also a public intellectual, contributing to the debates in Mauritania, which gives his story a reflexive dimension and an agency lacking in other obscure Guantánamo detainees. In short, Slahi tells a story that is distinct from the typical Guantánamo and terrorism-linked profiles, a story that is situated in a specific African context.