Sermons in Solitary Confinement by Richard Wurmbrand and published by Classics.
The author writes "Out of fourteen years in jail under the Communists in Romania, I spent three years alone in a cell thirty feet below ground, never seeing sun, moon or stars, flowers or snow, never seeing another man except for the guards and interrogators who beat and tortured me. I seldom heard a noise in that prison. The guards had felt-soled shoes and I did not hear their approach. I had no Bible, nor any other book. I had no paper on which to write my thoughts. The only things we were expected to write were statements accusing ourselves and others. During that time I rarely slept at night. I slept in the day-time. Every night I passed the hours in spiritual exercises and prayer. Every night I composed a sermon and delivered it and these are some of those sermons."
