MARTHA’S LOVE LIFE took a dark turn when she was introduced to Rudolf Diels, the young chief of the Gestapo. He moved with ease and confidence, yet unlike Putzi Hanfstaengl, who invaded a room, he entered unobtrusively, seeping in like a malevolent fog. His arrival at a party, she wrote, “created a nervousness and tension that no other man possibly could, even when people did not know his identity.”