Born on a small farm in rural Poland, Barbara Mueller Walling left home at the outbreak of World War II, fleeing to German-occupied Warsaw to evade Nazi conscription into forced labor in the Third Reich. She was 17. Working as a waitress in a chic German restaurant, she fell in love with its owner, Edmund Mueller, who was 28 years her senior. The war had rendered Edmund-a Pole of German descent-precariously neither Pole, nor German. This afforded...