FIRST PART – IN SPAIN
At the home of the Marquis of Calatrava, near Seville…
Dinner is coming to an end in the castle dining room. The Marquis takes leave of his daughter Leonora and retires. A galloping horse is heard... It is Don Alvaro, the son of a Spanish noble and the last princess of the Incas. Leonora and Alvaro are in love. The young girl’s father opposes their union and they have decided to elope. The Marquis surprises them. Alvaro refuses to fight a duel with him. He offers him his pistol and Leonora rushes between them. As it drops, the pistol goes off and fatally wounds the Marquis. The old man falls to the ground cursing his daughter. Alvaro and Leonora manage to escape.
“Sinfonia”
During his flight, Alvaro was wounded by a servant. Leonora has taken refuge with a female relative. The two lovers are separated. Carlo, the Marquis’ son, has set out on the trail of the fugitives.
Eighteen months later. An inn in the village of Hornachuelos, at sunset...
Leonora, disguised as a young man, has set off in search of Alvaro. Guided by a muleteer, Trabuco, she comes to spend the night at the inn. Already desperate, she is yet more terrified when, among the clients of the inn, she recognises her brother Carlo. The latter believes her to be dead and, disguised as a student, is in search of Alvaro. Preziosilla the vivandière enters. She announces that war has broken out between the Italians and the Austrians. She is recruiting soldiers and exalts the pleasures and advantages of military life. She predicts the future for several of those around her and sees through Carlo’s false appearance. The latter is forced to buy her silence. But he is also highly intrigued by the “strange traveller” accompanying Trabuco. The prayers of a pilgrims’ procession making its way to the jubilee interrupt his investigations. Leonora will take advantage of this to flee after hearing her brother tell the story of one of his friends, his own story in fact! Thus learning that Alvaro is alive, she believes herself to be abandoned.
In front of the Madonna degli Angeli monastery in the middle of the night...
Leonora comes to the monastery gate. After imploring the virgin, she asks for Father Guardiano’s protection. She has come to seek refuge with God, amidst the solitude of those who have chosen to forsake the world. After a long hesitation, Father Guardiano accepts to help her. She will find refuge in a holy place, near the monastery, where no one will come to disturb her isolation.
In the monastery church, at dawn... 
The monks are all gathered together. Father Guardiano explains to them that a lost soul has come to repent and atone for its faults inside the sacred hermitage, which no one is to approach on pain of divine malediction. He gives his blessing to Leonora. Once the ceremony is over, she sets off to her mountain retreat.

SECOND PART – IN ITALY
Two years have passed. In the vicinity of the Velletri battleground, by night, inside a military camp...
Don Alvaro has joined the army under a false name. He bewails his miserable fate. Believing Leonora to be dead, he hopes to die in battle and thus join her in the afterlife. Gamblers are quarrelling. Alerted by their cries, Alvaro intervenes and saves the life of an officer attacked by cheats. The officer is none other than Carlo, Leonora’s brother. He too has an assumed name. They both swear eternal friendship. Battle breaks out. Alvaro, gravely wounded, asks Carlo to burn the letters he entrusts to him without reading them if he should die. Surprised by this request, and after a certain hesitation, he finally examines the documents and discovers among them a miniature portrait of his sister. He now realises the true identity of his new friend and swears to at last avenge his father’s death.
A few weeks later.
A patrol is inspecting the outskirts of the camp. Alvaro has recovered. Carlo has at last found his trail. He introduces himself under his real name and challenges him to a duel. Soldiers run up and separate them. Remaining alone, Alvaro throws down his sword and decides to enter a monastery. He flees.
Day breaks over the countryside...
Vivandières and soldiers bustle about the camp, encouraged by Preziosilla and her “friends”. A pedlar buys up for a pittance all that the soldiers have pillaged during the battles. Mothers bewail the fate awaiting their sons, young recruits. These future soldiers are immediately consoled and motivated by Preziosilla. The vivandières drag them into a boisterous tarantella from which there suddenly emerges a monk caught up in the general commotion. It is Brother Melitone. Having become a military chaplain he seeks to preach the good word, but his sermon attracts nothing but jeers and he is obliged to flee. Preziosilla and her partners set up a makeshift theatre. They improvise a show for the soldiers. Exalting war and victory, she invites them to join in her famous “Rataplan”.

THIRD PART – IN SPAIN
Five years have passed. It is winter. The courtyard of the Hornachuelos monastery, in the evening...
After entering the monastery Alvaro has become Father Raphael. As food and drink are distributed to the poor who are dying of cold, the latter sing the praises of this mysterious monk, thus provoking the jealousy and anger of Melitone much to the amusement of Father Guardiano. Carlo, even more decided on revenge, has discovered Don Alvaro’s hiding place. In a dramatic scene, he manages to force Alvaro to abandon his pious serenity. They go out to fight a duel.
A hermitage near the convent: an abandoned and remote place...
Leonora, still tortured by her tragic memories, begs heaven for peace for her soul. The battle between Carlo and Alvaro obliges her to return to her retreat. Carlo is fatally wounded. He asks his adversary to hear his last confession. Alvaro, now judging himself unworthy of carrying out his ministry, runs off in search of the “hermit”. Suddenly thrown together, the two lovers are terrified. Each believed the other to be dead. Leonora rushes to the side of her dying brother. The latter, unyielding, fatally wounds her before dying. Leonora passes away peacefully, begging for divine compassion. Father Guardiano invites Alvaro to bow before the will of God.