The boy Fortunato is outside of his family's house, playing a horn while his parents are away. Shots ring out in the distance, and Sanpiero runs in, wounded. Fleeing the police, he asks Fortunato to hide him. Fortunato asks for and gets some money in return, and hides Sanpiero, the smuggler.
The police arrive, led by Gamba, who is a distant cousin of Mateo. They search the house and try to get information out of Fortunato, who resists with juvenile evasions until Gamba tempts the boy with an enamel-encased watch. Fortunato takes the bribe and reveals Sanpiero.
Mateo and his wife return. After Gamba tells them of their son's help in capturing Sanpiero, the wounded man curses the Falcone household for betrayal as he is carried away. Mateo has only one thing to do to preserve the honor of his family: he takes his son away from the house, says prayers with him, and kills him with a single gunshot.