At Thermopylae, Hercules comes upon the blissful sight of the double spring. The fountain is held sacred to Persephone, who is the wife of the king of the underworld. He saves a woman in distress and then finds himself heavily aged. Then he finds his youth restored upon meeting Persephone and letting her guide him inside the realm hidden inside the double spring. The double spring allows him to experience his mortality as never before as he journeys through the spring, which takes him to a place between the realms of the living and the dead. Hercules learns his purpose in guarding the hot gates as he must face his own mortality.