ACT I. Sicily, late-thirteenth century. Fortune has turned against the outlaw Gualtiero, whose pirate fleet has been defeated by the forces of Ernesto on behalf of King Charles. As the people of Caldora look anxiously to sea during a storm, Gualtiero and his crew are cast ashore. He is recognized by his old tutor, Goffredo, who now lives as a hermit. Gualtiero asks what has become of Imogene, whom he still loves. Goffredo is reluctant to answer, but when the people say the local duchess-Imogene herself-is on her way to help the shipwreck victims, he urges Gualtiero not to let himself be discovered by his enemies.
Imogene arrives at the beach and greets the survivors. Questioning Gualtiero's friend Itulbo, she learns to her distress that the pirate captain may have been lost during the recent sea battle. As an aside to her companion, Adele, Imogene confides a recent dream in which she imagined Gualtiero wounded and dying upon a beach; her husband accused her of causing the man's death and dragged her away. Gualtiero, briefly stepping outside the hermit's hut, recognizes Imogene. When the sound of his voice stirs further memories of her lost love, her companions see how upset she is and lead her back to her nearby castle of Caldora.
That night, outside the castle, the shipwreck victims have been enjoying the duchess's hospitality. Itulbo, afraid their identify will be discovered, wants them to quiet down, but they share more drinks before returning to the castle. Imogene emerges, having sent Adele to find the mysterious stranger whose voice she heard on the beach. Gualtiero approaches, unrecognized at first, and answers her solicitous questions about his misfortunes, which she compares to her own. When he reveals his identity and accuses her of betraying him, she replies that she had to marry Ernesto in order to save her aged father from death in prison. They are interrupted by ladies-in-waiting, who bring Imogene's child. Gualtiero seizes his enemy's son, threatening to do away with him. At the sight of Imogene's distress, he relents and gives the boy back to her, then hurries away.
Scarcely has Imogene breathed a sigh of relief when word comes that her husband has returned triumphant from the sea battle. His soldiers march in, singing of their exploits. Ernesto joins them-and cannot understand why Imogene seems depressed at such a glorious moment. Her anxieties are justified when Ernesto sends for the leader of the shipwrecked crew and proceeds to question him. Itulbo answers in Gualtiero's stead, saying they are from Liguria, "where all strangers are welcome." Ernesto notes that the Ligurians sheltered his enemy, Gualtiero, and provisioned the pirates, so he orders the crew held until he can find out more about them. Upon Imogene's intercession, however, he agrees to let them leave, if they will do so the next morning. Aside, Gualtiero threatens Imogene with dire consequences if she will not meet him one more time, while Ernesto wonders why he mistrusts these strangers. Because Imogene is afraid to meet with him, Gualtiero starts to throw himself on Ernesto, but Itulbo and Goffredo restrain him. Imogene swoons, revives, and is led away, while Ernesto fears for her sanity. Gualtiero, recklessly longing for revenge, is dragged away by his restraints.
ACT II. Imogene's ladies-in-waiting express concern for her as she rests in her chamber. When they have left, Adele tells her she may now go to meet Gualtiero, who has sworn not to leave without seeing her. Ernesto enters, however, challenging her indifference. She admits she still loves Gualtiero, "but as one loves a man dead and buried." Then Ernesto receives a note saying Gualtiero lives and is present in the castle. Imogene warns of sure bloodshed, but Ernesto, furious, dashes from the chamber.
On the castle terrace toward daybreak, Gualtiero refuses to be persuaded by Itulbo that they should make their escape immediately, as Ernesto stipulated. Gualtiero wants to defy Ernesto, risking his own men's lives if necessary. Itulbo leaves as Imogene arrives for a final rendezvous with Gualtiero, who delivers an ultimatum: Either she flees with him, thereby punishing Ernesto, or Gualtiero stays and fights. Refusing to dishonor her marriage vows, no matter how unwelcome, she asks Gualtiero to forgive her and to flee from Ernesto's wrath. As she bids him farewell, Ernesto draws near and sees their last embrace, then bursts forth to challenge his rival. Both men are spoiling for a fight and ignore Imogene's pleas to kill her instead. They rush off. With Adele, who has arrived to comfort her, Imogene heads after the men, hoping to stop them.
In the castle later that day, the duke's followers form a funeral procession and swear to avenge his death at the hand of Gualtiero. To their surprise, Gualtiero enters. He throws down his sword and says he is ready for vengeance, but they reply he must first be condemned by a tribunal. Turning to Adele, he asks her to carry his final farewell to Imogene, in the hope that she will pray for him in death. He leaves with the knights to face his fate. Imogene wanders in, distracted, imagining she has saved her son from assassins and brought him to his dying father. When the boy actually arrives, she speaks consolingly to him until a trumpet sounds from the Council Chamber, announcing Gualtiero's condemnation. Realizing, despite her madness, that he is about to die, she envisions the scaffold and declares herself ready to die too, of grief.
-- courtesy of Opera News