The pirate captain Nebula tried to bury her stolen trunk of jewels in a seaside cave. But the horrifying Arachne, half spider and half woman attacked her. When Hercules and Iolaus showed up, they joined forces with Nebula to try and destroy Arachne before she could destroy them. Arachne swooped down from the ceiling of the cave and snatched Iolaus. Finding his friend wrapped in a cocoon, Hercules took on the spider-woman. During the fight he held up a reflective shield, and when Arachne saw her own image, she backed away in horror, right into a flaming cocoon.

Hercules' brother, King Iphicles of Corinth, was not with his wife when she died -- he was out controlling rioting soldiers. For this he blamed the vetern warriors led by Ajax and demanded they leave Corinth without dedicating a statue. Hercules and Iolaus, friends of Ajax, tried to intervene. But deadly battles broke out when Iphicles killed Phidias, the statue's designer. Ajax tried to kill Iphicles as retribution, but he ended up devoured by giant sand worms. Tired of the madness, Iphicles relented by officiating at the dedication of Phidias' statue and extending land to the veterns.

Nebula took Hercules and Iolaus to Sumeria, where the angry gods were leveling cities. To remedy the situation, King Gilgamesh took Hercules with him on a series of physical trials in a pyramid, where they retrieved a chalice of sacred nectar. But Gilgamesh betrayed Hercules by drinking the nectar and crushing the cup, becoming a disciple of the demon Dahak. Next, Gilgamesh tried to scarifice a warrior heart -- Nebula's. But Iolaus, who was in love with Nebula, saved her by taking the dagger himself. Hercules destroyed Gilgamesh, but he was too late for Iolaus, who died in his arms.

Stricken with grief over the loss of Iolaus, Hercules vowed to bring him back from the Sumerian version of the Underworld. Nebula, who confessed her love for Iolaus in his final moments, accompanied Hercules on his journey. The son of Zeus rappelled down into a cave to confront Dumuzi, the Sumerian god of the Underworld. Dumzumi had been collecting human souls in order to survive, ever since King Gilgamesh had destroyed the sacred chalice. But Iolaus had already crossed over to the Underworld and was lost forever. Hercules' cry of rage shattered the mirrors surrounding Dumuzi's lair, destroying the god.

Hercules and Morrigan were enjoying life on the island of Eire until they found the Druids slaughtered. Recognizing the work of the demon Dahak, Hercules and Morrigan returned to Sumeria. There, they found Nebula had been bothered by waking dreams of her dead love, Iolaus. When Hercules visited Iolaus' tomb, he found it empty -- and turned to find Dahak behind him, in the body of Ioalus. As they fought, hercules could not bring himself to slay his friend, even though he knew it was no longer Iolaus. Dahak escaped, with Hercules, Morrigan and Nebula in hot pursuit.

Hercules and his friends followed the demon Dahak to Corinth, where Dahak -- in Iolaus' body -- had set himself up as the people's savior. He wanted to return the world to a time when the Titans ruled. Hercules and Zarathustra, a man who resisted Dahak's teachings, found the Stone of Creation and joined Nebula, Morrigan and Jason at the Dark One's fortress. Hercules used the stone to harness the light of dawn. The light became metallic and bound Dahak to his own altar. Hercules then prepared to perform an exorcism that would allow Iolaus to rest in peace.

Dahak, chained to the altar in the body of Ioalus, hatched a plan to kill Ares, which would give him the power to break his bonds. Meanwhile, the demon showed Hercules how he had seduced Iolaus at the moment of death. Apppearing as Hercules, Dahak promised Iolaus the power to set everything right in the world. With time running out, Hercules was sucked into the spiritual world, where he found the real Iolaus. The two friends fought side-by-side once more, sending Dahak into a fiery chasm. Then they siad good-bye, and Iolaus disappeared into a shaft of light.

Hercules jumped through a vortex into the Netherworld. There he found his evil double, the Sovereign, as well as the cowardly double of his late sidekick, Iolaus. Disguising himself as the Sovereign, Hercules learned that Nebula, the parallel world's evil ruler, conspired with Ares to imprison the Gods of Olympus in the Labyrinth of Eternal Memory. Hercules and Iolaus battled a giant snake and entered the labyrinth. After defeating Ares and Nebula, Hercules freed the gods. The parallel Iolaus, wishing for a bright future in a new world, jumped through the vortex with Hercules.