'Once Upon a Time' Season 3 Spoilers: Snow Meets Ariel, The Gang Tries to Save Neal [Video]

On the latest episode "Once Upon a Time," it was revealed how an upstanding Navy lieutenant became the devious Captain Hook.

In the fairytale land that was, Killian Jones (Colin O'Donoghue) and his brother board a ship with a sail made of Pegasus feathers to fly to Neverland to find a plant that can cure any ailment. Once in Neverland, they meet Peter Pan (Robbie Kay).

Pan tells them that the plant, Dreamshade, does not cure--it poisons. Killian's brother does not believe it, so he exposes himself to the plant, which kills him. Pan cures his brother with water from a magical spring, but the brother dies once they land back home. Killian is so angry that the king would send them on such a mission that he denounces allegiance to the Navy and becomes a pirate. He then renames the ship the "Jolly Roger."

Back in present day Neverland, Emma (Jennifer Morrison) wants to give word to Henry to not lose hope, because his family is near. Meanwhile, Hook leads Charming (Josh Dallas) to Deadman's Peak, where he wants to give him the same water that Pan gave his brother. Hence, Charming will be cured, but he will never be able to leave Neverland. Charming drinks the water and is healed.

Emma then uses Regina (Lana Parrilla) to use a Lost Boy's heart to control him. The Lost Boy then goes to Henry and gives him half of a compact mirror through which he can communicate with Emma. After the gang reunites and Charming says that Hook saved his life, Emma thanks Hook by giving him a passionate kiss.

Hook is later approached by Pan, who tells him that Baelfire, Henry's father, is in Neverland. He leaves it up to Hook--who obviously has a crush on Emma--to tell Emma that he's alive. Pan has captured Neal (Michael Raymond-James), and tells the Lost Boys to hang him up "next to the other one," meaning there is another person imprisoned with him.

On the next episode, simply titled "Ariel," viewers will be introduced to the famous red-headed mermaid. 

The synopsis reads: "Back in the Fairy Tale Land that was, when Ariel (JoAnna Garcia Swisher) saves Snow White from drowning in the ocean's depths, Snow returns the favor by helping her new friend get acquainted with Prince Eric, with whom she has fallen madly in love with. Meanwhile, Emma, Mary Margaret, David and Hook attempt to save Neal, who is imprisoned in one of Pan's encampments, and Regina and Mr. Gold begrudgingly team up to find a way to take down Pan."

It will also be revealed whether or not Hook tells the others that Neal is on the island. Colin O'Donoghue told TVLine: "Hook spent 300 years looking for revenge because he lost one woman. Who knows what would happen to him if it happened again?" But, by the same token, "He is desperately trying his best to be a team player, to try and help save Henry. Because he now sees there's more to life than that side of things," O'Donoghue said. But he warned that Hook can't be changed very easily.

"It's very easy to go back to old habits," he added. 

Watch the promo for "Ariel," which airs Sunday at 8/7c on ABC.