With the money they make from farming their land too meager to ensure their livelihood, Don Plutarco, his son Genaro and his grandson Lucio play music for extra income. One day, when they return home, they discover the army has attacked their village and taken away the ammunition of the local guerrillas, a group in which Genaro is involved.
Don Plutarco, using his weak appearance to advantage, approaches the military occupying the village in the hopes of recovering their valuable goods. His talents as a violinist impress the captain of the army so much that he asks the old man to return every day to play for him. These daily visits enable him to steal the weapons and ammunition out from under the noses of the soldiers. His plan, however, is not without faults.