In Pietro Mascagni's tragic opera, a soldier returns home from war to reclaim his former fiancée, only to find that she's married someone else in his absence, leading to jealousy, betrayal, and murder.

Bewildered, Don Camillo learns that Peppone intends to stand for parliament. Determined to thwart his ambitions, the good priest, ignoring the recommendations of the Lord, decides to campaign against him.

Don Camillo (now bishop) and Peppone (now senator) return to the town of Brescello and rekindle their friendly rivalry.