en Cuevana 3. Frederick, Prince of Pilsen, rebelling against his coming marriage with Princess Bertha of Thorwald, meets Hans Wagner, a brewer, and his daughter Nellie. The brewer, mistaking the prince for the son of a friend, asks him to join in a banquet. Hans becomes intoxicated, dresses up in a uniform, and is then mistaken by a coachman for the prince and brought to the palace