Whatever you do, do not mess with Hades (Greg Germann)! It looks as if Hook (Colin O’Donoghue) is learning that the hard way in episode 14 of “Once Upon a Time” Season 5.

Last week’s episode of the ABC fairy tale drama concluded with Hades dropping some unfortunate news on the pirate. For every soul that his friends allow to escape the Underworld, he’s got to choose one to stay behind. Right now they’ve successfully freed three souls – which means Hook has to carve three names into the gravestones. But Hook was never one to play by the rules.

Episode 14, titled “Devil’s Due,” picks up with Hades asking Hook for the three names. However, Hook defies the ruler of the Underworld and tells him he’s not going to choose. Hades anticipated Hook not playing along, and he’s got a backup plan. He sends him down the river of lost souls.

Meanwhile, the Storybrooke gang is still working on tracking Hook down — Gold (Robert Carlyle) included. He’s desperate to return home to Belle (Emilie de Ravin) and knows that the only way he’ll be able to get back to Storybrooke is by helping the others find Hook. Fortunately for Gold, his estranged father, Peter Pan (Robbie Kay), has left him his pawnshop to do with as he wishes. The twist is that Peter Pan still wants passage back to the land of the living. He leaves a note for Gold, writing that he hopes they can be a family again. Gold takes advantage of the shop and uses a crystal ball to check on Belle. However, what he sees makes him drop the ball in horror.

Emma (Jennifer Morrison), Snow (Ginnifer Goodwin), David (Josh Dallas), Regina (Lana Parrilla) and Robin (Sean Maguire) still don’t know where to find Hook, but Gold has a good idea where to start — and it involves his ex-wife, Milah (Rachel Shelley).

A flashback to the Enchanted Forest gives “Once Upon a Time” viewers a glimpse at Rumple and Milah’s marriage before he became the Dark One. The only thing keeping them together was their son Baelfire. However, a poisonous snake almost took their beloved child away from them. They had 24 hours to get Baelfire the cure, but the healer who had the magical potion wanted 100 gold pieces. That was money that they would never have. But Milah had no plans on losing her son. She told Rumple to kill the healer and steal the potion.

Back in the Underworld, Gold finds Mila helping schoolchildren cross the street. She’s not happy to see her ex-husband, but her attitude changes when she learns that Hook is trapped down there as well. When Gold asks for her help in retrieving him from Hades, she agrees. It’s an awkward joint effort, and gets even more awkward when Gold introduces her to Emma.

“You’ve been with my former lover and my son?” Milah asks when she meets Emma for the first time.

There is no competition when it comes to Hook, though. Milah wants to find Hook just as much as Emma does. And surprisingly, Hades is hiding him in the basement of the Underworld version of Emma’s Storybrooke house. Magic is preventing them from passing through, but the trio is able to join hands and pass through the spell.

The basement leads to the river of lost souls, and Emma uses the opportunity to tell Milah that Baelfire moved on and is happy. Milah’s grateful to hear that, and asks Emma if she can continue with her on to the river of lost souls. Emma agrees, and the trio set out to get Hook. But once they reach the end of the river, Gold says he’s staying behind. He wants to make sure that they keep their boat, but Milah doesn’t trust her ex. She promises Emma that she’ll stay behind and warn her if Gold attempts anything.

Elsewhere in the Underworld, Regina is taking advantage of her situation by searching for another soul. She’s having trouble locating this mysterious person, and enlists the help of Cruella (Victoria Smurfit). Surprisingly, Cruella is very helpful. She gives Regina a map of the graveyard, along with a key to deciphering the gravestones. If the stone is standing, then the person is still in the Underworld. If the stone is knocked over, then the person moved on. But if the stone is cracked, then the person got dragged to a place worse than the Underworld.

It turns out that the person Regina was looking for was Daniel, her first love. But Daniel’s not in the Underworld. His stone is knocked over, which means he was able to find peace and move on.

Back underground Emma is finally able to find Hook. The catch is that he’s tied up and slowly getting lowered into the river of lost souls. Emma’s got limited time and must cross a thin metal bar in order to get to him. It’s a tough path to cross, but Emma’s able to get there and remove Hook before he becomes just another lost soul.

It seems as if rescuing Hook is too easy. And that’s because it is. Back at the boat, Hades appears before Gold and uses his magic to freeze Milah.

Another flashback to the Enchanted Forest reveals that Milah first met Hook at the local tavern after she sent her husband on a quest to kill the healer and steal the potion for Baelfire. Hook came to Milah’s rescue after a drunk bar patron began to get a little too handsy with her. Milah was grateful that Hook intervened, and was flattered when he asked her to join him on the water. However, at that point she was still devoted to her husband, no matter how strained their relationship was. Hook promised her that his offer remained on the table.

While Milah was at the tavern, Rumple followed through on his word and went to kill the healer. He initially tried to steal the potion, but his clumsiness resulted in him waking up the healer. Rumple pulled out his knife, but couldn’t follow through. That’s when the healer offered Rumple another deal. He would hand over the cure, but Rumple had to agree to give him his second-born son.

Rumple made the deal and proudly returned home. Milah was ecstatic that her husband got the cure for Baelfire, but was horrified when she learned at what cost. Rumple promised it wouldn’t be a problem because they just wouldn’t get pregnant again. However, Milah was upset that he decided her future for her.

Cut back to the Underworld and Hades wants to make a deal with Gold. Turns out he’s a big fan of the Dark One and loves how many souls he sends his way. He wants to send Gold back to Storybrooke so he can do what he does best. But in return he wants Gold to burn the boat to prevent anyone else from leaving.

What would Gold get out of dealing with Hades? Hades simply promises not to kill him along with the others.

Gold decides to partner with Hades, and Milah watches in horror as Gold torches the boat with his magic. But what comes next is much worse. He sends his ex-wife right into the river of the lost souls, preventing her from ever finding her peace by reuniting with Baelfire.

Emma and Hook race back to Gold, and the Dark One spins a story about Hades burning the boat and killing Milah. This only fuels Hook’s hatred for Hades.

The trio manages to make it back to the top and reunite with the others. Although they have no boat, Regina attempts to use her magic to split Emma’s heart for Hook. Unfortunately, the plan backfires. Regina attempts to pull out Emma’s heart, but finds magic stopping her. When they go to the cemetery they find out why.

Hades had given Hook the opportunity to choose three names, and when Hook refused, Hades made the decision for him. The ruler of the Underworld carved Regina, Snow and Emma’s names into the stones, condemning them to the Underworld forever.

Annoyed that his companions managed to fail yet again, Gold left them to return to his shop. But Gold didn’t go where he said he was going. Instead he went to Hades to follow through on his deal of returning to Storybrooke. Hades had a change of heart, though. He had been watching Gold and was curious why he broke the crystal ball when he saw Belle. It turns out Gold wasn’t using the ball to look for Belle. He was trying to use it to see his son. The crystal ball showed him Belle because she’s pregnant with his second child.

Another flashback reveals that Rumple revisited the healer after he became the Dark One. He didn’t like that he owed him anything, and killed the healer to make his contract void.

All of Gold’s bad karma seems to have finally caught up with him because that contract with the healer carried over to the Underworld. The healer signed over the contract to Hades, and he’s holding it over Gold’s head. He warns Gold that all magic comes with a price, and that he needs to do something for him before he can go home to Storybrooke.