Admetus (Admète), king of Thebes, is dying.
Apollo's oracle announces that Admetus can live if someone takes his place.
Alcestis (Alceste), the king's wife, offers herself to the underworld.
Alcestis asks the gods if she can see her husband one more time.
The city celebrates as the king returns to health, but no one can understand why Alcestis weeps.
The truth slowly emerges and she bids farewell to life.
Admetus implores his wife to renounce her pact, but she remains true to her word and dies. After yet more mourning Apollo is forced to revoke his oracle's pact and restores Alcestis to life, reuniting her with her husband.