As Sheriff Graham deputizes Emma, the ground shakes and a giant sinkhole mysteriously appears at the edge of town. But a curious Henry’s life is placed in danger when he decides to explore the innards of the sinkhole to see if its contents can link the inhabitants of Storybrooke to the fairytale world. Meanwhile, back in the fairytale world, Jiminy Cricket yearns to leave the family business and transform into the person he wants to be.

Regina and Mr. Gold play dirty politics and take opposite sides when Emma runs for a coveted Storybrooke public office against Sidney. Meanwhile, back in the fairytale world that was, Rumplestiltskin tries to track down the ultimate power source in order to help his son avert the horrors of a meaningless war.

After Mr. Gold's house is robbed, Emma keeps a close eye on him when it looks like he wants to track down the criminal and dole out some vigilante justice as payback, and Valentine's Day finds Mary Margaret, Ruby and Ashley having a girls' night out. Meanwhile, in the fairytale land that was, Belle agrees to a fateful deal to give up her freedom in order to save her town from the horrors of the Ogre war.

After Ruby quits Granny's diner and with her self-esteem at an all-time low, Emma hires her as an assistant in order to help Ruby discover what it is in life that she's good at; and Emma continues questioning David about the disappearance - and possible murder - of Kathryn. Meanwhile, in the fairytale land that was, Red Riding Hood yearns to run away with her true love. But she, along with her fellow townspeople, are virtual prisoners when a bloodthirsty wolf continues on its relentless killing spree.

Mr. Gold attempts to uncover the true identity of August, Emma confronts Regina about her involvement in Kathryn's disappearance, and David tries to apologize and reconcile with Mary Margaret. Meanwhile, in the fairytale land that was, Rumplestiltskin agrees to comply and do whatever it takes if his son can find a way for him to safely give up his powers and turn back into the loving man he used to be.

Henry pleads with Emma to stay in Storybrooke and continue her quest as the savior of the fairytale dwellers, and Regina concocts a plan that could rid her of Emma forever. Meanwhile, back in the fairytale land that was, Snow White enlists the aid of her fellow fairytale cohorts to attack the Evil Queen and save Prince Charming's life.

Regina continues to seek a way to regain her powers; David continues his quest to find Mary Margaret and Emma; the seven dwarves discover what happens when one of the townspeople tries to leave Storybrooke's city limits.

Emma follows Capt. Hook up a beanstalk in hope of finding a magical compass; a fellow thief wants to make an honest woman out of Emma.

A stranger may be a threat to the true identity of the townspeople; Cora tries to reunite with Regina.

Cora and Regina try to overpower Mr. Gold; dark magic tempts Mary Margaret; Rumplestiltskin offers his services to Cora.

Hook helps Regina with a plan to transport her and Henry back to Fairytale land; Emma grows increasingly suspicious of Tamara; the queen asks Rumpelstiltskin to transform her so that she can kill Snow White.

In their continuing quest to find Peter Pan's hideout and save Henry, Hook suggests tracking down Tinker Bell in the hope that she will lead them straight to his camp. Pan reveals to Henry why he has brought him to Neverland and in the Enchanted Forest, Neal has a plan that could transport him to Emma, but it would involve using one of Robin Hood's most precious possessions. Meanwhile, in the Fairy Tale Land that was, Tinker Bell offers to help Regina improve her life.

In New York, Hook tries to make Emma remember by something very powerful: true love. In the Enchanted Forest, Regina, Snow, and Charming all team up to defeat a very powerful witch. In another world's past, a young girl learns how to use wizardry only to be hunted by a mob.

After Zelena steals Regina's heart, Regina casts a spell so that she can speak across the realms to her dead mother, Cora, to discover the truth about why she abandoned Zelena, and Belle stumbles across what Zelena's ultimate end game is. Meanwhile, in the Fairy Tale Land that was, young Cora is duped by a man claiming to be a prince and finds herself alone and pregnant. But a chance meeting with a real prince could lead Cora to the royal life she's always craved, but she must keep her pregnancy a secret or risk losing everything.

While desperately trying to find her sister Anna, Elsa accidentally traps them both inside an ice cave. Regina secludes herself from the town and Henry. With the townspeople considering Mary Margaret their leader, she faces her first leadership task in trying to re-start a generator and restore the town’s electricity after Elsa freezes and damages the power lines. Anna tries to teach a meek David to fight Bo Peep.

The Snow Queen attempts to pit Anna and Elsa against each other; with her powers out of control, Emma seeks assistance from Gold; Regina's quest takes a surprising turn.

Hook tells Emma that her fate is at stake in Gold’s plan while Regina leads the villains on a wild goose chase. Henry makes a breakthrough in his search to find the Author, but Mary Margaret and David need a moment to reconsider the best course of action. In a Fairy Tale Land flashback, Snow and Charming search for a way to ensure their child will grow-up to be a hero. When a traveling peddler directs them to visit a kindly old hermit, Snow and Charming are presented with a choice that could secure their child’s goodness, but at a price that will haunt them for years to come.

Emma returns to Storybrooke to reunite Lily with Maleficent while Regina and Robin struggle to cope with the implications of Zelena's pregnancy. When Gold's health takes a turn for the worse, Isaac looks to a new ally for help procuring the magic ink he needs to re-write history. In a Fairy Tale Land flashback, Cora returns from Wonderland to beg Regina's forgiveness on the anniversary of Daniel's murder. Cora vows to help her daughter find true love, but Regina remains suspicious of her mother's intentions.

In Camelot, the heroes feverishly work to free Merlin. Determined to help Emma, David embarks on a quest to retrieve a magical relic that Regina could use to communicate with the imprisoned sorcerer, but, when David leaves, Arthur insists on joining him because the dangers ahead are greater than he can imagine. Meanwhile, Mary Margaret discovers the fate of her old friend Lancelot. Back in Storybrooke, Arthur seeks David’s help to catch a thief who threatens the safety of the citizens of Camelot. Across town, Emma reaches out to a conflicted Hook as she sets about her plan to draw Excalibur from the stone.

In Camelot, Merlin spearheads a mission to reunite the dagger with Excalibur so he can use the weapon to save Emma from the darkness threatening her soul. With Zelena in tow, Hook, Mary Margaret, David, Regina and Robin steal into Arthur’s castle to take the broken sword from the maniacal king. Meanwhile, Merlin brings Emma along on a journey to confront his ancient nemesis and retrieve the sacred spark he’ll need to reforge Excalibur. Both parties are tested, but one suffers a blow that could derail the entire operation. In a flashback to long before the Age of Arthur, young Merlin finds purpose after he is blessed with magic and immortality, but when he falls in love with a young refugee named Nimue, everything changes for Merlin, as their romance starts a chain of events that touches every one of our present day heroes.

Hook's captivity takes a dark turn when Hades threatens to condemn him to the River of Lost Souls after Hook refuses to choose which three of his friends will have to remain in the Underworld. Meanwhile, Gold is suddenly eager to help Emma, Snow, David, Regina, Robin and Henry find Hook so he can return home to Belle; but in order to do so, he must find his ex-wife Milah in the Underworld and ask for her help. In Fairy Tale Land flashbacks, Rumple and Milah face a life-or-death crisis concerning their son, Baelfire, that forces Rumple to make a deal that will haunt him.

Hades turns to the heroes to ask for help with getting Zelena back from Rumplestiltskin and Peter Pan. In return, he offers to take all their names off their tombstones. However, when Hook is still unable to leave, he and Emma must journey into the depths of the Underworld. Meanwhile, Cruella De Vil is determined to keep the heroes trapped in the Underworld. In flashbacks, Emma searches for answers about her family and makes an unexpected friendship.

As Storybrooke continues to welcome the new arrivals from the Land of Untold Stories, families, friends and enemies are reunited once again. When 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 laboratory for his work.

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.

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. 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 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.

Henry’s Storybrooke family help him search for Cinderella, and Hook encounters an unexpected foe who threatens the group’s success. Meanwhile, in Hyperion Heights, Jacinda searches for a way to see Lucy with some unwelcome assistance from Henry.

Feeling like a third wheel as Henry and Cinderella's relationship strengthens, Regina is surprised to find herself needed by Drizella, who is searching for magic. But when a brutal truth is revealed, it could lead Drizella down a dangerous path. In Hyperion Heights, Roni seeks Weaver's help in finding answers, and Tilly offers Rogers some intriguing advice concerning Eloise Gardener.

When Drizella threatens the realm with a dark curse, Henry and Ella take extreme actions to protect Lucy and the others; and Regina is forced into making an unimaginable choice. In Hyperion Heights, Roni recruits Henry to travel to San Francisco to search for her sister, but when he learns Lucy has fallen unconscious, Henry rushes to be by her side. Meanwhile, Gothel earns the trust of Anastasia and the consequences of their budding relationship could prove to be fatal.

Henry grapples with an important decision when a job prospect in New York threatens to take him away from Jacinda and Lucy, but a revelation in the case of The Candy Killer could make it even harder to leave Hyperion Heights. Meanwhile, Margot confides in Tilly, and in a flashback, Hook helps Henry find a way to prove himself to Ella.