Karl Stern has never thought of himself as a Jew. But the bullies at his school in Nazi-era Berlin, don't care that Karl has never been in a synagogue or that his family doesn't practice religion. Demoralized by attacks on a heritage he doesn't accept as his own, Karl longs to prove his worth.

So when Max Schmeling, champion boxer and German national hero, makes a deal with Karl's father to give Karl boxing lessons, A skilled cartoonist, Karl has never had an interest in boxing, but now it seems like the perfect chance to reinvent himself.

But when Nazi violence against Jews escalates, Karl must take on a new role: protector of his family. And as Max's fame forces him to associate with Hitler and other Nazi elites, Karl begins to wonder where his hero's sympathies truly lie. Can Karl balance his dream of boxing greatness with his obligation to keep his family out of harm's way?