Thirteen-year-old Jakob's family has hidden their true identity as Jews and are living as Catholics in Budapest during World War II. One day, in a burst of loyalty, Jakob decides to reveal that he is Jewish, putting his whole family in danger. Jakob hopes his best friend Ivan, a Christian, will help his family but comes to believe that Ivan has abandoned them. Sent as a prisoner to Auschwitz, Jakob is kept alive by his passion for revenge against Ivan. When Jakob is finally freed, he discovers that Ivan, too, made a choice that day, a choice that changes everything Jakob thought was true.