What was Kristallnacht? How was Max saved this night?

In 1935, Max loses his job for being a Jew. The Nurmenburg Laws are passed, barring Jews from having German citizenship and marrying Germans. On November 9, 1938, Kristallnacht ("Night of Broken Glass"), Jewish stores and homes across Germany are attacked. Walter provides an opportunity for Max to hide, but Max initially refuses to leave his family; he ultimately does so. Max's mother gives Max a piece of paper with Hans Hubermann's name and address.