In 2009, Harper's Magazine sent war-crimes expert Lawrence Douglas to Munich to cover the last chapter of the lengthiest case ever to arise from the Holocaust: the trial of eighty-nine-year-old John Demjanjuk. Demjanjuk's legal odyssey began in 1975, when American investigators received evidence alleging that the Cleveland autoworker and naturalized US citizen had collaborated in Nazi genocide. In the years that followed, Demjanjuk was stripped of his American citizenship and sentenced to death by a Jerusalem court as "Ivan the Terrible" of Treblinka--only to be cleared in one of...