It was April 5, 1943, and the Gestapo would arrive any minute. Dietrich Bonhoeffer had been expecting this day for a long time. He had put his papers in order -- and left a few notes specifically for Hitler's men to see. Two SS agents climbed the stairs and told the boyish-looking Bonhoeffer to come with them. He calmly said good-bye to his parents, put his Bible under his arm, and left. Upstairs there was proof, in his own handwriting, that this...