The author himself later transformed it into a play, L'Arlesienne, for which Bizet wrote the well-known incidental music. From the play Leopoldo Marenco derived the libretto for Cilea's opera. The opera opens with the old shepherd Baldassarre in the Castelletto farmyard telling a story to l'Innocente, younger son of the widow Rosa Mamai, owner of the farm. With the break of dawn the goat collapses to the ground, as the sun kisses her and closes her eyes in death. L'Innocente is called so because he is slightly retarded.
Local superstition has it that an idiot child brings good luck to the household.
Nevertheless, l'Innocente is neglected by everyone except Baldassarre. Rosa's brother Marco has been alerted to gather information about this unknown woman whom Federico wants to marry. Rosa's goddaughter Vivetta arrives at the farm. She has always loved Federico and is disillusioned to learn of his obsession for l'Arlesiana. During the conversation between the two women, all of a sudden Rosa gives a start to see l'Innocente up on the edge of the window of the hayloft.