On December 30, 1977, the Kenyan writer Ngũgĩ wa Thiong’o was arrested. If the coarse toilet paper at Kamĩtĩ Maximum Security Prison in Nairobi was meant to be punishing, “what was bad for the body was good for the pen.” Ngũgĩ wrote the notes that became Detained: A Writer’s Prison Diary on that toilet paper. He also wrote the classic novel Devil on the Cross, which has been published in a new edition by Penguin.