In a flashback to the Enchanted Forest, a young Snow White is called upon to protect her kingdom while her father is away but she has no idea what to do. She runs away and falls down a hunter’s trap. She’s rescued by a young Hercules. He encourages Snow to fight the bandits and offers to help train her.
She stands up to the bandits but fumbles her arrows and fails. Hercules must come to her rescue. Turns out the bandits are on Regina’s payroll, hoping to turn the villagers against Snow White so she can become Queen. Instead, Snow learns how to fight and she becomes a hero.
In the Underworld, Hook helps another woman escape the underground prison and the three-headed hell hound, Cerberus, in the hopes that she will get a message to Emma.
Emma and Regina search for Hook in the woods and find the woman Hook helped escape. She tells them where to find him but that they’ll never get past Cerberus.
Mary Margaret finds Hercules tombstone and decides she has to find him and help him with his unfinished business in the hopes that he will help them free Hook. Mary Margaret finds Hercules. He died as a teen. She tells him that his destiny is to kill Cerberus but Hercules says the hero in him died.
Henry and Robin go back to the Mayor’s office to find town schematics. Henry finds Cruella de Vil in the office. She wants to go back to the real world and The Author (i.e. Henry) is the only one who can send her back. She says the quill he broke is in the Underworld because it was alive and had unfinished business. Henry doesn’t tell Robin he ran into Cruella.
Hades captures Hook after the Cerberus wounds him. Emma, Regina, Snow and Hercules go to the entrance and meet Hades, who is Hercules uncle. Snow learns the the Cerberus is what killed Hercules and sent him here. Hades threatens them all and gives Emma, Killian’s hook.
Snow realizes that Hercules can’t fight Cerberus alone. They must fight him together. Snow, Hercules, and the mystery woman from Hades, Meg, attack Cerberus together and kill it. Then Meg and Hercules remember that Cerberus killed them both before they were sent to the Underworld. With their unfinished business complete, Hercules and Meg are able to move on to Olympus.
Thanks to encouragement from Regina, Mary Margaret tells everyone that she wants to be known as Snow White from here on out because Snow is the hero who never gives up.
Hades is angry that Meg was allowed to leave the realm thanks to Hook helping her escape. He tells Hook that for every soul his friends are able to free, one of them will have to stay in the Underworld and Hook will have to choose who?