The charms of the sorceress Armida (Armide) have overwhelmed a large number of the Crusader knights of Godfrey (Godefroi). However, the most noble and valiant knight, Rinaldo (Renaud), has proved immune to her charms. Armida has dreamt that she falls in love with Rinaldo at the very moment that he kills her.
She tells her uncle, Hidraot, king of Damascus, that she will only marry the man who defeats Rinaldo. A soldier announces that all the Christian prisoners have been rescued - by Rinaldo.
Rinaldo is seeking further glory. His companion warns him to beware of Armida's power. Armida and Hidraot prepare to ensnare Rinaldo through magic. Rinaldo appears and is enchanted by demons and the beauty of his surroundings. Armida is determined to kill the sleeping Rinaldo, but on seeing him she is filled with love. Demons transport them both to a desert.
Armida recognizes that Rinaldo's love for her is reliant on magic, whereas her love for him is
uncontrolled. She summons Hatred to help rid her of her passion, but rejects this plan before her love is affected.
Two knights are to rescue the enchanted Rinaldo.They are armed with magic weapons which
enable them to overcome monsters and resist the spirits sent to seduce them.
With Rinaldo in her palace, the besotted Armida is plagued by premonitions of disaster. She decides to consult her evil spirits and leaves Rinaldo surrounded by pleasures.
The two knights enter and release him from her magical charms. Armida returns and fruitlessly implores Rinaldo to stay. Left alone, Armida rages with mounting desperation. Summoning demons to destroy her palace, she flies off in her chariot.