It portrays the Spanish patriot Agustina of Aragon, known for her role at the 1808 Siege of Zaragoza against Napoleon's French forces.

French troops led by Napoleon besiege the city of Zaragoza.

Agustina de Aragón (Aurora Bautista) is a young woman who, upon learning that her boyfriend has sold out to the enemy, breaks up with him and falls in love with a Baturro guerrilla.

Gustine walked through the dead and wounded to a cannon and opened fire.

Thus, Agustina managed to maintain the situation until Spanish reinforcements arrived.