on a blustery Friday in late winter, Kurt Bauer strolled nervously into the shadow of the city’s most dreaded building. The structure itself wasn’t imposing. Five stories of stone with a mansard roof, it had once been a hotel, then an art school. Its elegant rows of high windows suggested a place of light and enlightenment. Its current name suggested otherwise: the Reich Main Security Office, home to the Gestapo and the SS.Kurt had already approached the entrance once, only to have his nerve fail him. On his second try he again veered away, heading north toward the Brandenburg Gate while taking deep breaths of the chill morning air. After fifteen days of thought and planning, he had finally settled on a risky course of action, and by day’s end he hoped to have secured a safe future for his family and, more important, for Liesl and him.But first he had to go through with it.He had set out from Charlottenburg at sunrise, hoping to steel his resolve by making the four-mile journey on foot.