In Salta Province in 1817 during the War of Independence, the irregular forces commanded by General Martín Güemes carry out a guerrilla action against the Spanish army. The commander of a Spanish army contingent, Lieutenant Villarreal, is wounded, captured by the guerrillas, and put under the medical care of Asunción, the mistress of an estancia. She finds out from his idenfication paper that the Lieutenant, though serving in the Spanish army, was born in Lima. She persuades him of the justice of liberating America from Spain. The patriot forces receive help from the sacristan of a chapel located next to the grounds of the royalist troops. The sacristan fakes loyalty to the king, but during the battles he sends messages to the gaucho guerrillas hiding in the mountains by means of a messenger boy and by ringing of the bell.