Averilla del Alvaretti is set to marry the Conte della Piacca, forced into the union by her unfeeling uncle, when she meets the handsome Sylvio di Rosalva and falls in love with him. But Sylvios behaviour and origins are mysterious, and despite his professions of love, he abruptly breaks off the connection, sending Averilla a mortifying letter saying he never loved her.

Averilla marries the Conte della Piacca, who, she is pleased to find, is a kind and generous man, and not the tyrant she had imagined. Then, one night at a party with her husband, Averilla catches sight of Sylvio --...