Emma is at a movie theater to see Sword and the Stone in 1989. She steals an Apollo candy bar, but before she can eat it, a theater usher comes over and calls her out by name. He then cautions her about her actions, but it seems like he is implying more than just stealing a candy bar now. He’s giving her warnings about her future by telling her if she does bad things, then more bad things will happen.
Arthur pulls the sword from the stone on the screen just as the usher tells Emma that one day she will have a chance to remove Excalibur and she shouldn’t do it.
Lancelot and his riders are riding toward the real sword in the stone. They are worried about a prophecy, but those are soon forgotten when another knight attempts to take it, only to get poofed away. Arthur steps up and removes the sword no problem…only it turns out he only has half of it.
Storybrooke picks up shortly after the Once Upon a Time season 4 finale. Hook tries to call Emma back by using the dagger. When Emma doesn’t come, Regina points out that the dagger only summons people from the corner of your world, which means Emma is not in their world. We find out she is in the Enchanted Forest.
It turns out that Emma is not quite the Dark One yet. Rumple shows up to guide her on her dark journey. Rumple warns her but she tries to tell him that she won’t hurt the people she loves. Emma realizes that, if she’s in the Enchanted Forest, that means Merlin is here and he can destroy the darkness.
Hook visits the Apprentice, who tells him that Emma has gone where all Dark Ones go. He conjures a wand that can cross realms, but it requires part light and darkness to open it.
Regina takes the wand, but her struggle between good and bad over the years has resulted in her being firmly good, which means she isn’t much help. Hook says they have to turn to Zelena. Regina refuses to ask her sister, so Hook turns to Henry. He wants him to write Emma out of being the Dark One, but Henry tells him he destroyed the pen because it was too evil. Instead, he has Henry help him break out Zelena. Henry distracts while Hook confronts Zelena. He tries to take her heart, but she is prepared. And then she cuts her own hand off before re-growing it, which allows her to remove the cuff Regina put on her.
Regina knows Zelena will use her freedom to go to Robin first, which she does. According to Zelena, Robin is the key to everything. She disguises herself as Regina and brings Robin to the group. Zelena wants to trade Robin for the wand so she can return to Oz and raise her child there. Regina gives in and allows Zelena to open the portal, but she knew it would weaken Zelena which allows them to use her portal for themselves to find Emma.
The group hides in Granny’s and Regina uses Emma’s baby blanket to make sure the portal will take them to her.
Emma tries to find her way to Camelot and ends up almost killing a stranger who refuses to give her information. She is frightened and continues to refuse Rumple’s help, even after he helps her use her magic to transport herself. She needs to find a Whisp. A Whisp is a fairy born in “the Hill of Stone” and they answer your question when you bring them back home. Emma finds one and follows it and soon encounters Merida, who steals it from her.
Merida is worried about Emma’s intentions, but she assures her she’s not evil, but rather she was cursed.
They both realize they need the Whisp for different reason (Emma to get rid of the magic and Merida to save her brothers who were kidnapped). Emma refuses to fight her so Merida decides they should go together.
Merida’s brothers were kidnapped because of her. Also the clans in her land don’t approve of her as a Queen since she’s a woman. Emma convinces Merida to rest for the night, which is when Rumple shows up and tells her to kill Merida. The Whisp becomes property of whoever whispers to it first, so if Emma doesn’t get to it first, she is screwed. Emma resists and when she wakes up she finds Merida gone. Merida has already started taming the Whisp, but finds shooting arrows at Emma won’t work as Emma catches every arrow. Rumple encourages her to rip out her heart and Emma gets close to squeezing it when the Storybrooke Squad shows up.
Rumple disappears and Merida is saved. Merida thanks Emma for revealing her own darkness, because it has made Merida realize that she has darkness in her too. She was prepared to kill the people who took her brothers, but now she wants to show them mercy.
Emma tells them they shouldn’t have come. Snow gives the dark one dagger to Emma, but she refuses to take it. She gives it to Regina because she knows she will be able to put the emotion aside and do what needs to be done.
They bring Emma back to where Granny’s landed and are interrupted by King Arthur. Arthur reveals that Merlin prophesied her coming here a long time so they have been looking for her and Arthur is destined to reunite them. He brings the whole gang to the Camelot kingdom and it looks like a happy ever after.
Sneezy is acting as the sheriff when he finds everyone is back in Storybrooke, with no memory of how they got there. Also, six weeks has passed. Emma shows up all dressed in black and she is evil. She turns Sneezy into stone to prove it. Regina tries to stop her, but realizes she doesn’t have the dagger anymore. Emma has the dagger and she wants to punish them for what they did to her.