During the 1913 carnival, a man is stabbed to death in the confessional of Mainz Cathedral: Ferdinand Dörfler was the illegitimate son of the businessman Panezza, who never confessed to him. Ferdinand's brother Clemens is accused of fratricide by his own mother. The young Viola, who had come to Mainz from Italy, makes a confession: she loved Ferdinand and had been abandoned by him. Lolfo, who was unconditionally devoted to her, pursued Ferdinand and killed him. Lolfo commits suicide.