The clasp of time

Heracles and Iolaus battle the Lernaean Hydra

At the exact center of Metamorphoses 9, the sudden appearance of a rejuvenated Iolaus startles Alcmene, the mother of Hercules, and Iole, the daughter of Eurytus.

nam limine constitit alto
paene puer dubiaque tegens lanugine malas,
ora reformatus primos Iolaus in annos.

There, on the steep threshold, stood Iolaüs, Hercules’s nephew and companion, alive again, with the look of his early years, a hint of down on his cheeks, almost, again, a child.

The marvel on the threshold gives rise to the abrupt speech of Themis, which manages in one mouthful to pull together several threads of the tale of Theban cycle and link them with the usually unrelated story of Heracles:

She prophesied. ‘Thebes is now moving towards civil war, and, of the Seven against her, Capaneus will not be overcome, except by Jupiter himself. Two brothers, Eteocles and Polynices, will die of mutually inflicted wounds. Amphiaraüs, the seer, swallowed by the earth, still living, will gaze on the ghosts of his own dead. His son, Alcmaeon, shall avenge him, with his mother Eriphyle’s death, filial and sinful in the same act. Terrified at his own evil, exiled from home and sanity, he will be pursued by the faces of the Eumenides, and by his mother’s shade, until his wife,Callirhoë demands the fatal necklace, that Venus gave Harmonia, and until the sword, of his first father-in-law, Phegeus, in the hands of Phegeus’s sons, shall drain his son-in-law’s blood. Then at last, Callirhoë, the daughter of Acheloüs, as a suppliant, will ask of mighty Jupiter, to add years to her infant sons, and not allow the avenger’s murder to be unavenged. In anticipation of being moved by her prayers, Jupiter claims for them this gift that you, his stepdaughter and daughter-in-law, possess, and will make them men, in their childhood years.’ Kline

To make sense of Themis' very compact prophecy, a few identifications are in order: the epigoni are the sons of the original Seven against Thebes. Where their fathers failed, the sons eventually succeeded in taking the city, but their tragic destinies do not end there. A leader and key figure among the epigoni was Alcmaeon. His complex story is summarized here -- some of its key elements would include: 

His father was Amphiaraus, a hero of the Calydonian boar hunt, a favorite of Zeus and Apollo, and a seer who knew in advance that the first war of the Seven was doomed to fail. Amphiaraus' wife and Alcmaeon's mother, Eriphyle, was bribed by Polynices (son of Oedipus), who offered her the necklace of Harmonia to persuade Amphiaraus to support him in the war.

Amphiaraus made Alcmaeon swear that he would avenge his foreseen death, which is also prophesied by Themis:

subductaque suos manes tellure videbit
vires adhuc vates

the prophet king shall in the flesh behold his own spirits, engulfed by the yawning earth

After successfully taking Thebes with the epigoni, Alcmaeon fulfills his oath and kills Eriphyle. Like his father, he has the gift of foresight. Like Orestes, he is pursued by the Erinyes, goes mad, and seeks help from Delphi:

Alcmaeon is instructed by the oracle to find a land which did not exist at the time when he was polluted by killing his mother. Accordingly, he goes to a delta of the Achelous river, which was newly formed. There he marries Callirrhoe, the daughter of the river's god. She had heard of the famous necklace and robe of Harmonia, and asks Alcmaeon to get them for her. He complies, returning to Psophis and telling king Phegeus that he required the necklace and robe in order to be purified. Either Phegeus or his sons (Agenor and Pronous) discovers the truth from a servant, and they ambush and kill Alcmaeon.[7][8][9] In Apollodorus, Arsinoe, the daughter of Phegeus, chastises her brothers, who put her into a chest and sell her as a slave.[10] Meanwhile, Callirrhoe prays to Zeus that her sons will grow up instantaneously so that they might take revenge on her husband's murderers. Zeus grants this, and Amphoterus and Acarnan meet the sons of Phegeus at Agapenor's house, when they are on their way to Delphi to dedicate Harmonia's robe and necklace there. After killing them, Amphoterus and Acarnan continue to Psophis and killed king Phegeus and his queen, after which they are forced to flee to Tegea.  [Alcmaeon]

What isn't spelled out by Ovid, but is intimated in some versions of the story, is that Callirrhoe (daughter of Achelous) is having an affair with Zeus while Alcmaeon is off seeking the accursed neckace and robe of Harmonia. When Callirrhoe sees Zeus remove years from the life of Heracles' nephew Iolaus (so that he can defend the children of Heracles), she asks her lover to add those years (or subtract them, depending on how you look at it,) to or from the lives of her young sons so they can avenge the murder of their father, Alcmaeon.

Think of it as a kind of an accounting procedure by which time is reallocated but conserved. When Zeus assents, Ovid depicts him telling the gods that these matters are decided by the Fates:

Do any of you think you can overcome fate as well? Through fate Iolaüs’s past years were restored. Through fate Callirhoë’s children must prematurely become men, not through ambition or warfare. Even you, and I, too, fate rules, if that also makes you feel better. If I had power to alter fate, these late years would not bow down my pious Aeacus. Just Rhadamanthus would always possess youth’s flower, and my Minos, who is scorned because of the bitter weight of old age, and no longer orders the kingdom in the way he did before.’

Jupiter’s words swayed the gods: and no one could sustain their objection when they saw Rhadamanthos, Aeacus and Minos wearied with the years. (Kline)

We might find a parallel to what's happening to time here in what happened with Heracles and Lichas in space. Just as both the hero and the messenger ended up adding new real estate to the world, here time is moved around. Iolaus gets younger to keep the descendants of Heracles from harm, and his subtracted years are added to the sons of Alcmaeon so that they can avenge their father, who died avenging his father. With Iolaus, an older generation is rejuvenated to protect the offspring; with the sons of Alcmaeon, a too-young generation is accelerated to avenge their father.

Note: This is precisely what did not happen at Thebes, where Polynices and Eteocles, the sons of Oedipus, refused to share and exchange their alloted times as King.

So far, so good. But why does Themis (or Ovid) now intersect the narrative of Heracles, which has taken up most of Book 9 thus far, with the Cadmean history of Thebes, which took up much of Book 4?

Heracles' human "father," Amphitryon, and his mother Alcmene were Mycenaean descendents of Perseus from Tiryns, but were exiled and went to Thebes, where Amphitryon became a general. Heracles was born at Thebes under the reign of Creon, after the Seven and before the epigoni.

Heracles and his son Telephos

Thebes, Mycenae (Tiryns) and Argos become deeply intertwined in Themis' prophecy. Alcmaeon was from Argos. Over two generations, both his father Amphiaraus and he led armies against Thebes, and both generals were bedeviled by the necklace of Harmonia, which had been worn by Jocasta. The necklace interlaces Jocasta of Thebes, Eriphyle of Argos, and Callirrhoe, who seems to be a native of the new delta formed by the river Achelous, her father (recall that in Book 8 he had told Theseus of the nova terra he'd created).

When examined, the highly compressed speech of Themis is found to contain multitudes and manages to concatenate two mythic clusters, the stories of Heracles and the tragedies of Cadmus's Thebes, which, like two giant gears, mesh thanks to the device of time compression and elongation.

What is the point, though, of yoking these mostly separate histories? What is Cadmus to Heracles, or he to Cadmus?

Each is a major figure at the root of his own cycle of myths. Each is intended to establish order on earth by the gods, and both fail.

It takes generations for the house of Cadmus to collapse in fratricide and civil war. Heracles is born towards the end of the long reign of Theban descendants of Cadmus, and lives to see the epigoni effectively end that succession, though he had no direct involvement. Although he was intended to rule Argos and Mycenae, thanks to Hera's retardation of his birth, he is forced to serve Eurystheus, and fails to establish a dynasty that would protect his own children, the Heracleidae. After several wars and misunderstood oracles, they establish themselves in Mycenae and Argos, in part thanks to the rejuvenation of Iolaus.

Curiously, both Heracles and Cadmus are intimately associated with gifts of the gods, robes and serpents. (Besides the necklace, Hephaestus also gave Harmonia a robe at her wedding). Cadmus' story begins with his killing a giant water dragon, and he and Harmonia end their days intertwined as serpents; Heracles who ends destroyed by the blood of the Lernaean hydra, began his earthly sojourn by triumphing over serpents in his crib. Cadmus, an ancient hero, is a somewhat wooden figure, comparable in his absence of inwardness to heroes of medieval chronicles. Heracles is intense, baroque, dynamic, ever changing, breaking the frames that were supposed to define him. It is Heracles who, while he was dragging Cerberus from the underworld, took time to also bring Theseus (but not Perithoos) back from the dead.

The two giant mythic clusters seem to more than casually intertwine -- indeed, like the fateful necklace that cursed Thebes, they seem like two halves of yet one more beautiful, terrible, artful, deceptive gift of the gods -- the power to steal time:

The magical necklace, referred to simply as the Necklace of Harmonia, allowed any woman wearing it to remain eternally young and beautiful. It thus became a much-coveted object amongst women of the House of Thebes in Greek myths. Although no solid description of the Necklace exists, it is usually described in ancient Greek passages as being of beautifully wrought gold, in the shape of two serpents whose open mouths formed a clasp, and inlaid with various jewels.