ACT I

The hero Amadigi and Dardano the prince of Thrace have waited for night to fall before fleeing the enchanted realm of the sorceress Melissa. At the very moment of leaving, Dardano learns that Amadigi is in love with the princess Oriana, the very woman whom he himself adores. He makes a decision, however, to conceal his feelings.
Melissa enters. She attempts first by caresses and then by threats, to touch Amadigi`s heart, but he doesn´t return her love.There now begins a series of ordeals which the heroes have to surmount in order to rescue Oriana, who Melissa has imprissoned. Oriana and Amadigi are finally runited; they swear oaths of constancy and love until the others, in their jealousy, bring their idyll to a brutal end. Melissa conjures up a chorus of Demons and Furies, which carry off Oriana. Melissa „gloaths and laughs“

ACT II

Deceived by the magic spell, Amadigi sees in the water an image of Oriana kissing his rival and thus proving false. He faints. when Amadigi awakes, he covers Oriana with reproaches, calling her „perfidous, ungrateful and cruel“, Dardano bewails the fact that oriana continues to flee him. melissa lends him the shape of Amadigi. Oriana is taken in by illusion and the two of them are reconsiled; she confesses her love. Amadigi himself now enters. Dardano, thinking that he has not been seen, runs after his rival with the aim of killing him. But when Melissa reappears, it is to report the death of the Prince of Thrace at Amadigi`s hands. Once again Melissa threatens Oriana, but the latter pours scorn on her powers, claiming that neither pain nor suffering holds out any fears for her. Left alone, Melissa looks forward to „Arming all the Furies of hell“ against these perfidous traitors.

ACT III

Hoping to stir Amadigi`s feelings, Melissa has Oriana led in by the chorus of Demons and threatens her with death. the two lovers beg her mercy, but the sorcerer has no other thoughts than vengeance, to which end she calls on the shade of Dardano. The latter`s ghost appears, but announces that the gods now protect the faithful lovers: Melissa`s power are henceforth at an end. Melissa seeks to lay violent hand on the Princess, but a force more powerful than her own restrains her. She attempts once more to melt Amadigi`s heart, then stabs herself. On her death, the sorcerer Orgando enters. He announces the end of the others`torments and proclaims double wedding. Oriana and Amadigi swear eternal love. Shepherd and shepherdesses dance and sing „Rejoice, o ye loving hearts“.