Prussia at the time of the Wars of Liberation 1813 to 1815: The old Baron von Schranden, son of a French woman, made a pact with Napoleon Bonaparte's troops. This earned him the bitter opposition of his son Boleslav, who is loyal to the Prussian resistance. A break between father and son breaks out, and Boleslav leaves his parents' castle. Meanwhile, old Schranden's love of the French takes him so far that he even commits treason. He forces the maid Regine to lead the French troops over the Katzensteg in the rear of the Prussian Freikorps, which are fighting for the liberation of Germany from Napoleonic bondage.