The Titan Prometheus has been chained to a precipice in the Indian Caucuses for all eternity by the tyrant god Jupiter, as punishment for giving humanity the gift of fire. He has been imprisoned for three thousand years thus far, and every day an eagle is sent by Jupiter to peck out his organs, which grow back overnight.
A night, the sea nymphs Panthea and Ione—daughters of the Ocean and sisters of Prometheus’s wife, Asia—watch over Prometheus from the mountainside. Prometheus defiantly address Jupiter and tells him that, although Jupiter has supreme power over all the world, Prometheus does not envy him and would rather be chained to the mountain than reigning like Jupiter in Heaven. Although Prometheus cursed Jupiter when he was first bound, he has since forgotten the curse and asks the elements around him to remind him what he said. The elements admit that they remember his curse but are too afraid to repeat it. The Earth then speaks to Prometheus. She tells him that she is his mother and that his birth brought great joy to her as well as hope to mankind. Since his capture, however, the Earth has been sick with grief, sprouting poisonous plants and producing noxious vapors that have caused plague and famine among humanity.
The Earth calls up the Phantasm of Jupiter from the shadow world to repeat the curse for Prometheus, as the Earth does not dare repeat it herself for fear that Jupiter will punish her. The Phantasm of Jupiter approaches and Panthea and Ione cower before it, frightened by its likeness to the real Jupiter. The Phantasm repeats the curse, in which Prometheus states that he is the only being who will not bow to Jupiter and invites Jupiter to punish him as much as he likes because nothing the god does will make Prometheus respect his power. In his curse, Prometheus also hopes that Jupiter’s power will cause Jupiter suffering that outweighs the benefits he reaps from making himself the supreme authority.
After the Phantasm vanishes, Prometheus laments that he had wished pain upon another being. When she hears this, the Earth cries out that Prometheus has been conquered and that he is now a slave to Jupiter’s power. Ione, however, is confident that this is just a “passing spasm” and points out that the messenger God, Mercury, is flying towards them through the breaking dawn, followed by the Furies, monsters from the world of the dead and servants of Jupiter.
Mercury has been sent by Jupiter to make a deal with Prometheus, which will allow Jupiter to keep his power but give Prometheus his freedom. Prometheus rejects his offer and tells Mercury that he will never stop resisting Jupiter because Jupiter has enslaved the world and humanity. Mercury begs Prometheus to accept because he does not wish to watch Prometheus suffer, but Prometheus steadfastly refuses and tells Mercury to let the Furies at him.
Mercury sadly departs and the Furies attack Prometheus, taunting him with visions of suffering and cruelty acted out by humanity. They tell him that, although he has tried to help humanity by giving them fire, they have turned on each other with acts of violence, malice, and war. One man tried to preach a message of hope and peace, the Furies say, but his message was abused and distorted. Prometheus weeps for this man but refuses to speak his name, which he feels has now become a curse. The Furies vanish and Prometheus says that their torture has only increased his determination to defy Jupiter because it has shown him the terrible suffering on earth under Jupiter’s reign. The Earth then calls up a chorus of good spirits to comfort Prometheus. These spirits speak of a prophecy foretelling that Prometheus will kill death and bring new hope to humanity. Panthea tells Prometheus that he is deeply loved before she leaves to visit his wife, Asia, who is waiting in the valley below.
Panthea arrives just after sunrise and tells Asia that she is late because she was having strange dreams. Upon telling Asia that she cannot remember one of the dreams, Asia looks into her eyes, trying to divine the dream there, and is startled to see a shape beckoning her to follow. Panthea feels it too and cries out that it is her dream. The two nymphs follow the dream to the opening of a cave. A chorus of voices spur them on, and the two nymphs sink down, overcome by weakness, into the abyss, which is the entrance to the lair of the Demogorgon.
Panthea and Asia confront the Demogorgon on his throne and find that he is a shapeless spirit made of darkness. Asia explains to the Demogorgon that, when Prometheus first gave Jupiter knowledge, he gave it to him on the condition that Jupiter would “let man be free.” Jupiter however, enslaved mankind. Prometheus gave humanity fire in retaliation, so that they could tame the brutal environment that Jupiter had created for them. Jupiter then chained Prometheus to the mountain as punishment.
The Demogorgon tells Asia that all things in the universe “are subject to Eternal love,” and shows the nymphs a series of chariots racing around the earth’s perimeter. The Demogorgon says that these are the Spirits of the Hours and that one among them, who flies on a different route, is the Spirit of Love. The Demogorgon takes them to meet one Hour, the shadow of a destiny, who awaits them. The sea nymphs and the Demogorgon get into the chariot and ascend towards Heaven.
In Heaven, Jupiter is celebrating with the other gods. Although, he has not yet dominated the will of Prometheus, he is confident that he soon be omnipotent because he and the goddess, Thetis, have produced a child who is mightier yet than him. This child is the Demogorgon, who arrives in Heaven in the chariot of the Hour as Jupiter speaks. Jupiter is terrified when he sees the Demogorgon, who drags Jupiter down into his lair, ending his reign. Ocean and Apollo, the sun god, stand amazed as they watch Jupiter’s fall. They rejoice that they will no longer have to witness suffering on earth because the tyrant has been defeated.
Hercules frees Prometheus, and he is reunited with Ione, Panthea, and Asia. Prometheus tells Asia that there is a beautiful cave in which they will live together. He reminds Ione of a gift which Asia received on her wedding day, a shell which produces lovely music when blown, and tells her to give it to the Spirit of the Hour. He asks the Spirit of the Hour to fly around the world, sounding the shell, and the Earth delights that she can feel herself coming back to life now that Prometheus is free. She calls up a messenger, the Spirit of the Earth, to lead them to the cave which will be their dwelling.
The Spirit of the Earth calls Asia “mother” and talks with her playfully, telling her about the change which she has witnessed in the world since Prometheus has been free. The Spirit tells Asia that, as she was walking in a city, she heard a sweet music sounding in the night and all the people rushed outside to hear it. She watched as the people transformed, becoming joyful and filled with love. The Spirit of the Hour returns and tells them that he has done his job. He remarks on the transformation which has taken place among mankind, saying he has seen all the monuments of power abandoned and the courts of kings and rulers “unregarded” because man has no need for them.
Panthea and Ione go to sleep outside the cave of Asia and Prometheus. They wake to singing and witness the dead spirits of the Hours dancing in a funeral procession for the King of the Hours. They then witness a vision in which they see all the trappings of worldly power deserted and forgotten, as though at the bottom of the sea. As the Moon talks with the now gleeful Earth, water flows and plants begin to grow on the Moon’s surface. The Earth and the Moon rejoice at this new life and, from the deep, the voice of the Demogorgon sounds across the universe, spreading a message of “Love, Joy, Victory, and Empire.”