Arrested in 1960 for being philosophically and religiously opposed to communism, Armando Valladares was interned at Cuba’s infamous Isla de Pinos Prison (from whose barred windows he watched the failure of the Bay of Pigs invasion). His life in Castro’s gulag was a hell of violence and disease, putrid food and squalid living conditions, forced labor and solitary confinement, and hazardous escape attempts. Valladares survived by prayer and poetry. His writing, smuggled out to...