Who is left all on an empty plain with the city of Jerusalem visible in the distance?
A mountainside, at the magician's cavern. Goffredo and Eustazio are told by the Magician that Almirena is being held captive in Armida's palace at the mountain-top. Ignoring the magician's warning that they will need special powers, the pair set off for the palace but are quickly driven back by Armida's monsters. The magician then gives them magic wands that transcend Armida's power, and they set off again. This time they overcome the monsters, but as they reach the gates of the palace it disappears, leaving them clinging to a rock in the midst of a stormy sea. They climb the rock and descend out of sight.
In the palace garden Armida prepares to kill Almirena. Rinaldo draws his sword, but Armida is protected from his wrath by spirits. Suddenly Goffredo and Eustazio arrive, but as they touch the garden with their wands it disappears, leaving them all on an empty plain with the city of Jerusalem visible in the distance. Armida, after a last attempt to kill Almirena, also disappears as Rinaldo strikes her with his sword. The remaining four celebrate their reunion, while Goffredo announces that the attack on Jerusalem will begin the next day.
In the city, Argante and Armida, in danger from a common enemy, become reconciled and prepare their troops for battle. Goffredo's army advances, and battle finally commences. After a struggle for supremacy, Jerusalem falls to Goffredo; Argante is overcome and captured by Rinaldo, while Armida is taken by Eustazio. Rinaldo and Almirena celebrate their love and forthcoming marriage. Armida, accepting her defeat, breaks the wand which is the source of her evil power and together with Argante embraces Christianity. Goffredo expresses his forgiveness to his beaten foes and sets them free, before victors and vanquished join in a chorus of reconciliation.
Goffredo Eustazio