Hercules is finally a happy family man with his wife Deianeira, two young sons Aeson and Clonus, daughter Ilea and in-living centaur Nessus. When a trickster lures men to fight -using a fake- Eryx the Boxer, they are slain, so Hercules is called and slays the giant, but to Zeus' disappointment loses his temper when Hera shows by a peacock feather to be behind it again, and wrecks her temple. Nessus grumbles he's tired of the Herc-idolatry. The next call for help is made by Iole, from a city where people are killed by the fume from an entrance to the underworld which opened the earth there. He goes, but when an old woman recognizes the pendant the messenger gave Deianeira, saying it proves she belongs to maidens trained so well in the art of seduction they can get any man in their power, she finally believes jealous Nessus' warnings not to trust her with Hercules; they catch up with him, but he convinces her to trust him, then Nessus tries to rape her and dies cursing Hera's failure to protect him and showing Deianeira the cloak his blood drenches can secure his love again. They continue their journey, discussing their past and popularly exaggerated reputations. Iole demonstrates how her power can work for good, stopping an apparently ranging men from causing a major fight be touching him and diagnosing he just burnt his mouth at hot soup. She also stops Hercules killing Lycastus from her village, who attacks anyone he considers a rival for Iole. When they arrive at the village, the hell-mouth is stronger then ever. The half-god hesitates to believe his father Zeus, who answers reluctantly he can die, yet turns Ioles desperate plea -offering herself- down but when the cloak drenched in Nessus' blood nearly kills him as he puts it on setting out to return home and displays Hera's peacock-sign, he jumps into the underworld. He forces the ferryman Charon to bring him over the river Styx. Back home, a messenger tells his wife Deianeira the cloak killed him, driving her to despair as she gave it to him. Numerous monsters attack Hercules, but fail to stop him, nor can a hosts of villains he killed and cleverly makes fight each-other. The centaur Nessus is worse: he shows him Deianeira has committed suicide and is in Elysium, but enjoys Hercules' torment enough to grant him a 'last view', so he can jump into the magical image. There Hades tells him she is happy but oblivious of everything, even him, but parental love gets trough. When Hades tells him she still can not be relieved, he makes a deal: they can go if he delivers back the three-headed hell-hound Cerberus, who got loose and causes havoc all trough the underworld. The hunt is arduous, but his physical force and kindness at the right time do the job, so Hera closes the hell-mouth and Hercules' family can resume its earthly happiness too.