University professor Josef Held has never recovered from the loss of his wife. He has no intention of letting anyone new into his quiet, safe world, where the ticking clock in his mathematics classroom drowns out the beat of Nazi soldiers' boots. But when his Jewish pupil Michael comes to him, saying Jews will no longer be allowed to study, Josef can ignore the situation no longer. In an impulsive act of courage, he offers Michael a place to hide in his attic.