Phoebus Apollo has a son, Asclepius, who in time becomes a god of medicine and healing. Asclepius transgresses divine law by raising a mortal, Hippolytus, from the dead, and Zeus, in anger, kills Apollo’s son with a thunderbolt forged by the Cyclops. Apollo then slays the Cyclops, a deed for which he is condemned by Zeus to leave Olympus and to serve for one year as herdsman to Admetus, the king of Pherae in Thessaly.

Some time after Apollo completes his term of service, Admetus marries Alcestis, the daughter of the king of Iolcus, Pelias. On his wedding day, however, he offends the goddess Artemis and so is doomed to die. Apollo, grateful for the kindness Admetus showed him in the past, prevails on the Fates to spare the king on the condition that when his hour of death comes, they accept instead the life of whoever will consent to die in his place.

None of Admetus’s kin cares to offer himself in his place, but Alcestis, in wifely devotion, pledges herself to die for her husband. The day arrives when she must give up her life. Concerned for the wife of his mortal friend, Apollo appeals to Thanatos, who comes to take Alcestis to the underworld. Thanatos rejects his pleas, warning the god not to transgress against eternal judgment or the will of the Fates. Apollo declares that there is one powerful enough to defy the Fates who is even then on his way to the palace of Admetus. Meanwhile Alcestis prepares for her approaching death. On the day she is to die, she dresses herself in rich funeral robes and prays before the hearth fire to Vesta, goddess of the hearth, asking her to be a mother to the two children she is leaving behind, to find a helpmate for the boy and a gentle lord for the girl, and not to let them follow their mother’s example and die before their time. After her prayers, she places garlands of myrtle on each altar of the house and at each shrine prays tearlessly, knowing that death is coming. In her own chamber she weeps as she remembers the happy years she and Admetus lived together. Her children find her there, and she says her farewells. The house is filled also with the sound of weeping servants, grieving for the mistress they love. Admetus too weeps bitterly, begging Alcestis not to leave him. While he watches, however, her breath grows fainter, and her cold hand falls languidly. Before she dies, she asks him to promise that he will always care tenderly for their children and that he will never marry again.

At that moment, Hercules arrives at the palace of Admetus, on his way to slay the wild horses of Diomedes in Thrace as the eighth of his twelve labors. Admetus conceals from Hercules the news of Alcestis’s death so that he might keep the son of Zeus as a guest and carry out the proper rites of hospitality. Hercules, ignorant of what took place before his arrival in Pherae, spends the night carousing, drinking wine, and singing, only to awaken in the morning to discover that Alcestis died hours before he came and that his host purposely deluded him in order to make his stay in Pherae as comfortable as possible. In gratitude for Admetus’s thoughtfulness and in remorse for having reveled while the home of his friend was deep in sorrow, he determines to ambush Thanatos and bring Alcestis back from the dead.

Since no labor is too arduous for the hero, he sets out after Thanatos...