Here is a postcard written by Pastor Dietrich Bonhoeffer to his parents in 1931. Bonhoeffer was a key member of the German resistance, serving as an Abwehr agent and contact with the allies. He was executed at KZ Flossenburg on April 9, 1945 with co-conspirators in the Abwehr including: Admiral Canaris; General Oster; Captains Gehre and Struenk; and Judge Advocate General Sack.
A translation of this postcard has recently been published in Dietrich Bonhoeffer Works volume 11.
Colin