Apollo Arrives
In the kingdom of Lacedaemon, King Oebalus and his people prepare a sacrifice to Apollo at the god's altar. An earthquake shakes the ground — a sign that the gods are near. Then Apollo himself appears, taking mortal form to dwell among the people he loves. Young Hyacinthus is delighted: the god is like a shepherd among them, a friend and protector. But Zephyrus, the West Wind, is also present — and he is already watching with jealous eyes.
Jealousy
Apollo falls in love with Melia, the king's daughter. She returns his affection with delight — to rejoice, to play! But Zephyrus also desires Melia, and when she rejects him in favour of the god, his jealousy turns murderous. Unable to compete with Apollo, Zephyrus decides to destroy what the god loves most. During a discus game, Zephyrus seizes the moment: he hurls the discus at Hyacinthus, killing the innocent boy.
The Murder
Zephyrus runs to King Oebalus with a devastating lie: it was Apollo who killed Hyacinthus. The dying boy cannot yet speak to contradict him. Zephyrus is terrifyingly convincing — behold, he says, you see two rivals, and only one has reason to kill. Oebalus, mad with grief, believes every word. He and Melia turn on Apollo in fury: Depart, cruel one! The innocent god is banished from Lacedaemon, while the true murderer stands unpunished.
Truth Revealed
Oebalus is devastated — like a ship on a stormy sea, he has lost everything. Father and daughter mourn together: the son has fallen and the god has departed. But then the dying Hyacinthus speaks his last words, and with his final breath he reveals the truth: it was Zephyrus who struck him, not Apollo. The lie collapses. Zephyrus is exposed and banished, and Oebalus is consumed with remorse for driving away the god who loved his family.
Transformation
Apollo returns. He cannot restore Hyacinthus to life — even a god cannot undo death — but he can create something eternal from the tragedy. He transforms the dead boy's blood into a flower: the hyacinth, which will bloom every spring as a memorial. Oebalus and Melia beg forgiveness, and Apollo grants it. He takes Melia as his bride, and the three voices join in a final terzetto: at last, after the stormy thunderbolts, the sun returns. The eleven-year-old Mozart ends his first opera with a scene of grace, loss, and renewal.