Thespis, “the inventor of comedy,” is awakened from a drunken sleep. Thalie, the muse of comedy, and Momus, the god of satire, enlist his aid in staging a performance designed to correct the faults of mortals and gods alike – they will offer a reenactment of the means Jupiter once used to cure Juno’s jealousy. Love arrives, furious that she was left out. No play could give pleasure without her inspiration and they all promise a new entertainment.

Violent wind assails King Cithéron’s mountain. Mercury descends from the heavens, explaining that the storm is due to Juno’s jealousy. Cithéron has a solution. Platée, a water nymph from the neighboring marsh, is exceedingly vain but unattractive. If Jupiter feigns mad love for Platée, Juno will discover that her jealousy is groundless and they will be happily reunited. Platée arrives, and Mercury ascends to tell Jupiter the plan. Platée is convinced that Cithéron is in love with her. She becomes irritated by his indignant refusals. Mercury returns to tell Platée the great news: Jupiter is in love with her and will soon descend to declare it. A great storm ensues, but Platée and her marshy subjects welcome the torrent.

Mercury has sent Juno on a wild-goose-chase to Athens. He and Cithéron hide to watch the success of their plan. Arriving in a chariot with Momus, Jupiter first reveals himself to the enchanted Platée first as a donkey, then as an owl. Finally appearing in person during a rain of fire, he declares his love to the frightened Platée. Folly suddenly bursts in, having stolen Apollo’s lyre, and she sings a witty song, followed by several dances. Her flurry of frenzied genius encourages the union of Jupiter and his “New Juno.”

The furious Juno returns from Athens. Mercury persuades her to hide until the moment is right. The wedding procession arrives with a veiled Platée. She laments the absence of Hymen (god of marriage) and of Love. Momus appears, crudely disguised as Cupid. He presents Platée with Cupid’s gifts: tears, pains, wails, and hope, all of which Platée rejects. At the crucial moment, with no sign of Juno, Jupiter stalls. Finally, Juno bursts in and rips off the bridal veil to reveal Platée’s face. Astonished, Juno realizes her mistake and bursts out laughing. Happily reunited, all the gods return to the heavens, while Folly and the mortals tease Platée.