Derek Black grew up the heir apparent of a prominent white nationalist family. David Duke was his godfather. When Derek was 11, he designed the kids’ page for what is known as the first major internet hate site, created by his father. But after his ideology was outed in college, one of the only Orthodox Jews on campus — Matthew Stevenson — invited Derek to his weekly Shabbat dinners. What happened over the next two years, as the two of them became friends, is a roadmap for navigating some of the hardest territory of our time.