When Demeter uses her powers to make a beautiful spring day, her daughter, Persephone starts picking wild flowers and begins talking to a pig herder. Demeter appears to her daughter and tells her she should stay away from mortals. As Demeter goes to an old oak tree, Hades appears from the Underworld and abducts Persephone, while Demeter and Hercules look on.
Hercules asks Demeter what just happened and she says that Hades took Persephone to the Underworld. She asks Hercules for his help but he refuses, telling her it is a problem for the gods to sort out. She says there will be consequences for ignoring her request for help, she vows, "The Earth shall be as barren as my heart." The spring then quickly turns to winter, Hercules realizes it is the work of Demeter.
Hercules talks to a farmer, who tells him that they have no food, and they were relying on their crop to feed them and then the storm hit. Outside, Hercules tells Demeter that he has reconsidered. She says he will be allowed to go to the Underworld to bring Persephone back. He asks if she will put nature back on course and she gives him her promise that she will. She reminds him that once in the Underworld he must not eat the food and must not look behind him when he is leaving or he will be stuck there.
Once in the Underworld, Hercules sees his family playing and calls out to his wife. Meanwhile, Hades tries to convince Persephone to stay in the Underworld with him, but she says her mother would not like it. In the Underworld, Charon ferries Hercules across to the Elysian Fields. Deianeira sees him and greets him, she calls for the children and they come running to see their father. Hercules embraces them in an emotional reunion.
While reunited with his family, Hercules and Deianeira spend the night together. The next day, while playing with the children, Hercules meets Persephone and is shocked that Hades did not have her tied up. When Deianeira hears them talking, she knows Hercules will have to leave again and says she will prepare them something to eat. Persephone wonders why Deianeira does not know they cannot eat food from the Underworld. Hercules explains that Deianeira and the children do not know they are dead and are reliving the happiest moments of their lives.
Later, Hercules finds himself in Tartarus and Hades appears and warns him that he should watch himself if he wants to get back to the real world. Hercules says he is taking Persephone back to the surface. As Hades leaves, Hercules sees a man chained up with an apple just out of reach. Hercules goes to him and he tells Hercules, "A chain is only as strong as its weakest link." Hercules pushes the apple to the man and he takes a bite." Hercules wishes him luck and leaves.
He comes to a chained gate, and thinking back to what the man said, snaps the chains and goes through. On the other side, he sees Cerberus, who lets him pass. In Hercules chambers, Persephone is woken by Hercules, who tells her to get dressed. She tries to tell Hercules that Hades is not that bad and people forget he is also in charge of the Elysian Fields. Hercules asks if she likes him and she tells him that she finds him "Sexy." As Hercules and Persephone try to leave, some of Hades' guards come and Hercules beats them up.
As they run away down the stairs, Hades appears saying, "I won't be that easy." They start to fight and Persephone begs them to stop. After a short fight, they call a truce to talk it out instead. Hercules asks Hades if he has talked to Demeter about how much he loves Persephone. He says he has but she is too overprotective. He says Persephone is "the only bright spot in this whole place." Hercules says he has to take her back because he made a promise to Demeter, Hades says, "Iâll be doomed to the same emptiness you felt when you lost your whole family."
As Hercules and Persephone prepare to leave, Hades says he will changes the rules and let Hercules take his family back instead of Persephone. Hercules says he cannot, Hades sends them back to the Elysian Fields, and they are met by Deianeira. She asks where they have been and Hercules says they need to talk. He tells her that he does not belong there because he is not dead but they are. He says that he can take her and the children back with him. Hercules' daughter Ilea, offers Persephone some fruit.
Deianeira asks what the cost would be if they left, Hercules says Persephone would need to stay. He tells her that Demeter is causing problems on the surface. When she realizes people are dying she tells him he is needed there and should go. She makes him promise they will be together again some day. He says goodbye to the children and he and Persephone leave for the surface.
As Hercules and Persephone leave, Hades appears in the form of Deianeira begging Hercules to take her with him. A fissure opens in the ground and Hercules tells Persephone to hold on as he jumps across. They get to the other side and Demeter and Hades meet them. Hades says she cannot leave, but Demeter says Hercules made it back so she is free. Hades holds up some fruit, revealing that Persephone had eaten some of it. By the rules, she must stay with him.
When Hercules says that Persephone should decide where she wants to be, she says that she wants both. Hades says she has to choose, Hercules says she has. Because she only ate half the fruit, she could stay with him for half the year and the other half with her mother. Persephone decides she will stay with her mother first, so that she will put nature back on track. Hades says to Hercules that he acted bravely and shows his family one last time. He says he can wipe their memory of his visit, Hercules says if they will be completely happy again, then he should do it. Hercules thanks Hades and returns to the surface.