Set in the Jewish ghetto of medieval Prague, the film begins with Judah Loew ben Bezalel, the head of the city's Jewish community, reading the stars. Loew predicts disaster for his people and brings his assistant to inform the elders of the community. The next day the Holy Roman Emperor signs a royal decree declaring that the Jews must leave the city before the new moon. The Emperor sends the knight Florian to deliver the decree. Loew meanwhile begins to devise a way of defending the Jews.