Rolando , who was close to marrying the daughter of the Doge, is condemned after a highly unfair judicial process and locked up in Venice. Digging a tunnel with the aid of his cellmate, the pirate Scalabrino, Rolando succeeds to escape in a dramatic leap from the Bridge of Sighs. After numerous vicissitudes Rolando succeeds to unmask those responsible for the conspiracy and rehabilitate his own name.
