Jack Goldsmith is Shattuck professor of law. As such, he is known for his work on the legal aspects of terrorism, national security, and other fraught topics in international law. But like all faculty members, he has a life beyond the classroom and his scholarship. In his case, the complications of that personal life are the subject of the new book, In Hoffa’s Shadow: A Stepfather, a Disappearance in Detroit, and My Search for the Truth (Farrar, Straus and Giroux, $28).