Our heroes set out to stop Hyde, Emma develops a mysterious side effect, and Storybrooke becomes a haven for refugees from the Land of Untold Stories. Meanwhile, Regina and Zelena embrace their newfound sisterhood by becoming roommates, while Rumple tries to free Belle from the sleeping Curse with the help of a stranger. In flashback, Jafar confronts an afflicted Aladdin in Agrabah, and a secret about the Savior is revealed.
When a mysterious man from the Land of Untold Stories, who has a past with the Evil Queen, arrives in Storybrooke, David and Snow work together with Regina to neutralize the threat. Belle seeks Hook's help finding a safe place to hide away from her husband, Mr. Gold. The Evil Queen continues to try to win Zelena over to her side, while Emma resumes her therapy sessions with Archie and shares her terrifying vision of the future.
As Storybrooke continues to welcome the new arrivals from the Land of Untold Stories, families, friends and even long-lost enemies are reunited once again. When Ashley (Cinderella) searches for her step-family, intent on settling their unfinished business, Emma, Hook and Henry scramble to help her before it's too late. Meanwhile, Regina attempts to bribe Mr. Hyde for information about how to defeat the Evil Queen and Snow helps Dr. Jekyll find a suitable laboratory for his work. David makes a deal with Gold and delivers a message to Belle in exchange for new information about his father. In flashback, Cinderella attends a ball and meets her prince.
The Evil Queen and Hyde continue on their quest to steal Dr. Jekyll's serum; Snow looks forward to her first day back as a school teacher; and while Emma looks forward to Hook moving in with her, Hook finds himself trying to protect Belle from Mr. Gold, who has made sure she can't leave the confines of the pirate ship. Meanwhile, back in the past, Rumplestiltskin helps Dr. Jekyll complete his serum to separate a man's personality into two - good and evil - but his help comes with a hefty price.
In a flashback to Agrabah, Princess Jasmine recruits Aladdin to help her recover a secret weapon capable of breaking Jafar's hold on the Sultan and saving the city from ruin. Their quest takes them to the Cave of Wonders where Aladdin's fate is revealed. In Storybrooke, the Evil Queen tricks Hook and the Charmings and forces Emma to reveal her secret in an effort to divide the family. While the Evil Queen pampers Zelena, elsewhere in town, Regina and our heroes scramble to learn what became of Aladdin.
Emma tries to convince Aladdin to work with Jasmine to help Agrabah, while Regina teams up with Snow and David to free Archie from Zelena. The Evil Queen sows suspicion between Henry and Hook, even as Mr. Gold reminds her of his most important lesson. Meanwhile, in the past, Hook finds himself kidnapped by the mysterious Captain Nemo and held captive inside his legendary submarine, the Nautilus.
In a flashback to the Enchanted Forest, Bandit Snow dodges a bounty hunter known as the Woodcutter while shepherd David goes on a fateful journey to sell his family's farm. In Storybrooke, the Evil Queen threatens to destroy the town and everyone in it unless Snow and David surrender their hearts. As Emma, Hook and Henry prepare to defend Storybrooke, Snow, David and Regina search for a magical sapling created by the first spark of true love. Regina uses Gold's and the Evil Queen's burgeoning romance against them, and Zelena offers Belle some friendly advice.
Emma and Regina formulate a plan to trap the Evil Queen in a prison of their own making, while Snow and David adjust to life without each other. As Henry nervously prepares to take Violet to the school dance, the Evil Queen impersonates Regina to give him some advice that could lead him down a dark path. Meanwhile, Zelena agrees to help Belle, and together they enlist Aladdin to steal a magical object from Mr. Gold that could protect Belle and her unborn child from him forever.
In a Fairy Tale Land flashback, Rumple collects Jack and Jill's son as bait to lure a powerful being to him. Back in Storybrooke, Gold tells the Evil Queen that she must hug Zelena, and the EQ makes a decision that will change her relationship with her sister forever. When Belle discovers Gold's plans for their son, she convinces Hook and Emma to help her steal squid ink that can immobilize him, and, as a result, Belle is left to make a sacrifice that will affect the lives of everyone in Storybrooke. Meanwhile, Jasmine finds a genie-less lamp that she hopes to use to save Agrabah, and Aladdin finds a way to be her hero.
When she learns that our heroes possess a weapon capable of defeating her, the Evil Queen steals Aladdin's magic lamp from Jasmine and makes a wish that could sideline the Savior forever. Unwilling to wake Snow while Emma is missing, David works with Hook and Henry to hold the Evil Queen at bay in Storybrooke, as Regina goes on a rogue rescue mission. Meanwhile, Gold and Belle face a surprising danger to their newborn son.
With Snow still asleep in Storybrooke, David and Hook race to stop Gideon before he can confront Emma. Gideon makes a startling confession to Belle and Gold about his whereabouts while he was missing. Meanwhile, Regina struggles with the realization that everyone, perhaps even Robin, is better off in the alternate world where the Evil Queen was defeated. And when Emma inspires a familiar face to help her and Regina return home, she discovers the power to change her fate.
Before Hook takes the next step in his relationship with Emma, he wants to make sure David sees him as more than just a pirate. So when David asks Hook to help him uncover the truth about his father's death, Hook agrees. Meanwhile, Regina works to acclimate Robin to life in Storybrooke, but soon discovers he has a dark side that makes the task much more complicated than she anticipated.
When Gideon resumes his mission to hug Emma and become the Savior, Mr. Gold steps in to ensure that the use of dark magic does not poison his son. Meanwhile, Robin proves willing to ally himself with anyone offering the possibility of escape from Regina and Storybrooke. Hook gathers the courage to come clean to Emma, but not before she discovers he's been keeping a secret. And in a flashback to Fairy Tale Land, the legendary folk hero Beowulf sets his sights on Rumplestiltskin after the Dark One uses his powers to defeat the ogres and win the war for humanity.
Believing there isn't room in Storybrooke for both her and Regina, the Evil Queen sets out to eliminate her other half using Robin to bait the trap. Hook, determined to make things work with Emma, turns to his old friend Capt. Nemo for advice, but Gideon torpedoes his plan before he's able to set things right. In a flashback to the Enchanted Forest, the Evil Queen learns a surprising lesson about the true source of her misery.
When Hook finds himself trapped in another realm along with the Nautilus and her crew, he races to return to Emma before Gideon can execute the rest of his plan. In Storybrooke, Regina and Snow take Emma out to get her mind off Hook's disappearance. And in a flashback to Agrabah, Jasmine befriends Ariel, and together they set out to locate Prince Eric as the threat from Jafar intensifies.
Gold and Belle convince Emma to help Gideon, explaining that together they can stop the Black Fairy. Henry experiences a disorienting shift in his powers that forces Regina to seek counsel from the previous Author. Meanwhile, in Fairy Tale Land, Hook attempts to win the assistance of an old adversary by betting his most prized possession on a game of cards. And, in a flashback, the Black Fairy tortures young Gideon in hopes of molding him into the perfect apprentice.
Still trapped in Neverland, Hook aligns himself with Tiger Lily, hoping to find a way back to Emma. Back in Storybook, Regina works to break the sleeping curse that David and Snow are under, and Gold denies The Black Fairy, which brings the two of them to a fearsome impasse. In flashbacks, we learn what Snow and Charming sacrificed in order for Emma to fulfill her destiny as the Savior.
In flashback, Zelena befriends a young woodcutter who has been cursed and turns to her for help finding a new heart. Zelena is forced to choose between keeping her powers and her friendship with him. Meanwhile, in Storybrooke, Zelena decides to take on the Black Fairy and put a stop to her, once and for all, against Regina's wishes, and the Charmings disagree over Emma and Hook's wedding plans.
In flashback, after Rumple's mother, Fiona, learns from his fairy godmother that his destiny is prophesized, she does everything in her power to keep it from happening. Ultimately, Fiona will have to make a decision that will change the course of both their lives forever. Meanwhile in Storybrooke, Rumple faces a similar dilemma.
In flashback, Snow and Charming make a special wish that Emma will be protected. The result of their wish has the whole kingdom bursting into song which infuriates the Evil Queen. Meanwhile in Storybrooke, the Black Fairy announces her plans to unleash another curse on the town while Emma and Hook prepare for their wedding.
Henry awakens to a cursed Storybrooke and discovers Emma has been in the mental hospital, and the Black Fairy is the new mayor. Henry attempts to help Emma regain her memory while Gold tries to find out what has really happened to Belle.
Snow, Charming, Regina, Zelena and Hook are trapped in a crumbling Fairy Tale Land and desperately try to figure out a way to be reunited with Emma and Henry.