ABC’s Once Upon a Time season six episode six brings in Captain Nemo for an episode about the importance of family and not allowing the quest for vengeance to control your life. The episode titled ‘Dark Waters’ opens in the time of the Dark Curse. Captain Hook (Colin O’Donoghue) commands his crew of the Jolly Roger to move faster, but one man defies his command and then refuses to give his name when Hook asks for it. Instead, he says he has one question. “Is taking your revenge against the Dark One worth all the time you’ve spent chasing it?” he asks. Their conversation’s interrupted by what Hook thinks is a sea monster but is actually Captain Nemo’s ship, Nautilus. Nemo pushes Hook overboard before leaping from the Jolly Roger.
Back in Storybrooke, Hook enters Emma’s garage and hides the shears which could be used to sever her from being the savior.
Regina (Lana Parrilla) has a little chat with Zelena (Rebecca Mader) and the Evil Queen outside Zelena’s house. Regina lets the Evil Queen know that her attempt at masquerading as Archie didn’t work. Meanwhile inside the house David (Josh Dallas) and Snow (Ginnifer Goodwin) free Jiminy Cricket who was placed in a cage by the Evil Queen. Outside, the Evil Queen figures out Regina’s up to something else. Zelena runs back in and grabs her baby as Regina protects David and Snow from the Evil Queen’s magic. Snow says nothing the Evil Queen can do will tear them apart.
Jasmine (Karen David) and Aladdin (Deniz Akdeniz) share a booth at Granny’s, and Jasmine reminds him that even if he’s not the savior anymore, he can still help his people. He tells her he’s not the man she’s looking for.
Emma (Jennifer Morrison) gets a text saying Jasmine’s worried about Aladdin and she takes off leaving Hook and Henry to do whatever they want. Hook asks Henry (Jared Gilmore) to show him how to work his “video box,” but first Hook tosses out Henry’s pop tart. Instead, he’ll cook him a real pirate breakfast of grapefruit and boiled mackerel to prevent scurvy. Yummy!
Henry’s dumping the trash when the Evil Queen appears and asks if his “new father” is bothering him. Henry says Hook isn’t like her and would never hurt the family. The Evil Queen uses her magic to open the garage and leads Henry to the shears which Hook had hidden away. She tells him to ask himself what he’s going to do about it as those shears can destroy what makes Emma special.
Aladdin continues his thieving ways, breaking into a car and stealing a wallet. Emma catches him and he knows Jasmine sent her.
Hook goes outside, holding a video game controller and complaining about its design (it’s not made for people with hooks for hands). He spots the open garage door and sees the shears are gone from the box.
And now we have another flashback to the Nautilus where Hook attempts to escape and then quickly finds he’s under the sea. He thinks it’s dark magic but Captain Nemo explains he’s just on a ship many fathoms under the sea. Nemo believes his ship is Hook’s second chance, but Hook doesn’t want to be there any longer than he has to. Nemo spins a harpoon and says it’s enchanted to help him find wayward souls. He knows Hook’s heart is filled with hatred and he wants to fill it with something else: family. Hook’s expression becomes darker and he says no one will replace what the Dark One took. Nemo tells him he’s wrong and that he lost his own family and spent decades hunting down the men responsible. That hunt didn’t leave him satisfied but instead it left him with an empty heart. Nemo won’t let Hook off the ship because he needs his help with a mission. When the mission’s done, Hook will see this is exactly where he needs to be.
In Storybrooke, Hook catches up with Henry as he’s about to take a boat out to get rid of the shears Emma asked Hook to toss in the sea. Hook explains he only kept them to help Emma, and Henry angrily tells Hook he doesn’t get to make decisions for either him or his mother. Hook’s distracted and shushes Henry, and they both watch the Nautilus emerge in the harbor. They’re about to run but Nemo’s men are already on the deck and stop them. They’re both taken aboard the ship and Hook opens the big window to show Henry the view underwater.
Snow meets David at the hospital where an injured refugee from the Land of Untold Stories has just been brought in. He has serious injuries and would have died had he not been found. David heads out to see if he can find someone who knows this refugee while Snow stays behind at the hospital. She spots Belle (Emilie de Ravin) in the waiting room where she’s waiting for her first ultrasound. She didn’t tell Rumple she was visiting the doctor and has no idea how she’ll ever handle letting him be a part of their son’s life.
Back underwater, Hook reveals to Henry that he has a history with the Nautilus captain. Henry’s angry and believes this is all because Hook didn’t get rid of the shears when Emma asked. He also wants to know if Hook would have used them on her because being the savior is what she is – it’s what brought he and his mom together. But, the real problem is that Henry doesn’t want Hook to try and take over the role as his dad. Henry thinks they’ll be fish food soon anyway and Hook tells Henry they’ve been in tougher scrapes before. Then he says, “Remember the walking prisoner gag?” And Henry corrects him saying it was the Wookie prisoner gag, which completely confuses Hook who has no idea what a Wookie is. Henry’s done explaining things and Hook says he’ll come up with a plan of his own to get them out of this situation.
A leap back in time finds Nemo, Hook, and Nemo’s First Mate (Nick Eversman) exploring a path that’s very dangerous. Hook wants to know why the First Mate is so loyal to Captain Nemo and he explains as a child he grew up next to the docks, desperate to find the man who took his family and make him pay. He would have been killed but Nemo saved his life. He never found the person who wronged him, and he’s given up his quest for vengeance. Nemo interrupts to say they’ve found what they were looking for. As Nemo is preparing to approach the treasure chest, Hook tries to make a run for it but is grabbed by a massive octopus. The First Mate tries to save him but it’s Nemo who harpoons the octopus and frees Hook. Even though he’s stubborn, Nemo hasn’t given up on him. He even calls Hook a member of this family.
Rumple (Robert Carlyle) visits the Evil Queen at Zelena’s and she’s extremely flirty. She’s in a good mood because she’s driving Hook and Henry apart, and Rumple asks if she remembers her old lessons. He tells her she forgot the most important lesson: never take what’s his. He’s talking about the shears and he knows she had something to do with them going missing after Hook hid them. He asks if she really thinks the Sheers of Destiny work only on the savior and the Evil Queen figures out he wants to use them on Belle and the baby. The Evil Queen says the shears are long gone and he warns her she’s short on allies.
Emma drives Aladdin to the edge of town where she tells him to look closer at the Welcome to Storybrooke sign. She shows him where she hit the sign after trying to run when she learned she was the savior. She admits she also wanted to run after he gave her the shears. She was worried she might use them and that’s why she gave them away. She tells Aladdin to come back, face the people he disappointed, and try to make up for his mistakes. But, Aladdin doesn’t even know what happened in Agrabah after he left other than whatever did take place was his fault.
Hook recalls the story of what happened when he killed his own father, telling Henry it’s why he wants to make sure Emma, Henry, and the rest of the family stay together. Part of the story he’s never shared is that when he killed his father, he destroyed his younger brother. His name was Liam after Killian’s older brother, and that was too much for Hook. He killed his dad and left an innocent boy an orphan.
Back in time, Nemo opens the treasure chest and all it contains is a key. Nemo explains his ship serves as a refuge for people to repair their lives. The key will open the gateway to a place called Mysterious Island. It’s a place where Hook can start over, but Hook doesn’t want to give up his hunt for the Crocodile now. Nemo says Mysterious Island is a place where he never has to lose anyone again. He invites him to join his crew and see for himself. Just then Hook spots a knife on the table and Nemo says it belongs to his First Mate whose father was murdered while he was asleep in bed. It turns out the First Mate is Liam, Hook’s half-brother.
Henry asks if Hook’s trying to make up for what he did to Liam by helping him. Hook says he can’t ruin another family and Henry says he’s not going to. Hook thinks he has because now they’re trapped in Nautilus because of him. But, Henry has a plan. Henry gets all suited up to jump ship and escape to safety, however Hook can’t leave because there’s only one helmet (which Hook knew). Hook knows Henry has to make it back to his mom and just as Henry jumps in the water, Liam appears with the knife and says he’s been waiting a long time for this.
Flashback to Hook telling Nemo he has to leave before Liam figures out that he’s the man he’s been searching for. Liam tries to stop Hook before he can leave and Nemo tries to convince him not to attack Hook. Liam doesn’t listen and as he’s about to stab Hook, Nemo puts himself in front of him and is stabbed instead. Liam blames his mistake on Hook as Hook leaves the Nautilus.
Flash-forward and Liam tells Hook they actually made it to Mysterious Island but Hyde took Nemo. Hook points out that means he was in the Land of Untold Stories which means Nemo’s now in Storybrooke. Liam attacks and Hook won’t hit him back and won’t protect himself, and just then Henry – who was supposed to have left the ship – shows up and Hook knocks out Liam. Henry came back because he couldn’t ruin their family, but tells Hook not to push it when he asks if that means he thinks of him as family. Henry realizes Hook needs the shears because he loves Emma, and Hook promises he’ll never let Emma’s visions come true. Hook takes the shears and places them in Nemo’s treasure chest and they watch as it sinks in the ocean.
Aladdin meets up with Jasmine to apologize. He wants to fix things, even if he’s not the savior. He wants to help her restore Agrabah but Jasmine explains a sand storm enveloped the city and now it’s gone.
Snow works on flower arrangements at the hospital and tells Belle the unknown patient has a fighting chance. Belle’s ultrasound went well and she has two copies, although she’s still not sure she wants to give one to Rumple. She tells Snow that their son in her dream looked at Rumple with hatred, but that maybe it can turn out differently.
Liam wakes up in the Storybrooke hospital and Hook tries to explain again that he’s not the same pirate from all those years ago. And, Liam reveals he didn’t kill Hook in the Nautilus because if he did it in front of Henry, then Henry would grow up full of hate, just like he did. Liam wishes Nemo could see they made peace and just then Nemo’s wheeled into Liam’s hospital room.
Hook meets up with Henry who asks after Liam, and Emma admits she’s completely confused. Liam has a submarine? Why were Henry and Hook at the docks in the first place? Hook tells her the truth about the shears and that it’s all his fault. He tells her he couldn’t lose the one thing that helped save her but Henry made him see the error of his ways. He reveals the shears are now at the bottom of the ocean, and she’s not angry. In fact, she says she would have done the same thing in his shoes.
Rumple is glancing through a book when the Evil Queen enters his shop. She’s angry Hook and Henry are getting along, but she’s actually in his shop to make amends. She forgot the most important lesson he ever taught here which was to go after what she really wants. As they kiss, Belle slips one of the ultrasound photos under the door. Rumple asks the Evil Queen if it’s him that she wants, but she says there’s something else she’s after. She’ll need his help to get it. She hands him the shears, which an underwater creature retrieved for her. So, what is it she really wants? Snow White’s heart!