Katerina Bragadin is in love with Rodolfo, but suffers from the annoying attention of Angelo Malipieri, Padua's podesta, who wants to marry her at any cost. To get rid of his rival, he turns to the Council of Ten, the highest tribunal of the Venetian Republic. After Rodolfo is illegally imprisoned, the Podestà believes that he is completely out of the game. But events take an unexpected turn ...