My grandparents were Nazis. It took me until recently to be able to say — or write — this. I used to think of and refer to them as “ordinary Germans,” as if that was a distinct and morally neutral category. But like many “ordinary Germans,” they were members of the Nazi Party — they joined in 1937.

My grandmother, who lived to be almost 100, was not, as I knew her, xenophobic or anti-Semitic; she did not seem temperamentally suited to hate. Understanding why and how this woman I knew and loved was swept up in a movement that became synonymous with evil has been, for me, a lifelong question.

She and my grandfather grew up in a working-class suburb of industrial Dortmund, where unemployment was rife; it had been occupied by the French after World War I. They joined the Nazi Party to be youth leaders in an agricultural education program called the Landjahr, or “year on the land,” in which teenagers got agricultural training. My grandmother always maintained that she had joined the Nazis as an “idealist” drawn to the vision of rebuilding Germany, returning to a simpler time and, perversely, promoting equality.

In the Landjahr, sons and daughters of factory workers would live and work side by side with sons and daughters of aristocrats and wealthy industrialists. She liked the idea of returning to “traditional” German life, away from the confusing push and pull of a global economy. Through research, I understand the Landjahr program was part of Hitler’s larger “Blut und Boden” (“blood and soil”) vision of making Germany a racially pure, agrarian society. The “racially pure” part was not something my grandmother ever mentioned.