Marian falls under a freezing curse and the townspeople believe that Elsa is responsible. When Emma and David go to Robin's camp to look for clues, they find Will Scarlet, who leads them to the culprit. Meanwhile, in the Arendelle of the past, Elsa and Kristoff go to find the urn that Hans plans to use to imprison Elsa, and encounter the Snow Queen.

Emma’s powers run amok and she turns to Gold for help, Elsa and Anna’s relationship is tested, and the Snow Queen’s agenda is revealed.

Emma’s powers run amok and she turns to Gold for help, Elsa and Anna’s relationship is tested, and the Snow Queen’s agenda is revealed.

In order to infiltrate the Queens of Darkness as a spy for the heroes, Regina must prove she’s still willing to get her hands dirty. Meanwhile, Emma, David and Mary Margaret scramble to keep tabs on their undercover operative. Hook requests an unusual favor from Belle as Henry makes progress on his search for the Author. In a Fairy Tale Land flashback, Regina befriends Maleficent and helps her to rekindle her lost spark.

In fictional 1920s England, viewers meet a young Cruella, whose oppressive mother uses her Dalmatians to terrorize her daughter. Cruella is confined to her mother’s attic until a mysterious stranger arrives and empowers her to challenge her captor. In Storybrooke, Regina gains leverage to keep Gold from interfering with her plan to rescue Robin, but her trip to New York takes the backseat when she and Emma learn that Cruella has kidnapped Henry.

After receiving a cryptic warning from Lancelot about Arthur's intentions, Mary Margaret realizes Arthur may be the heroes' biggest threat, but when she is unable to convince David of the danger, she takes matters into her own hands. Meanwhile, Hook's unwavering love for Emma provides a glimmer of hope in her struggle against the unrelenting voice of Rumplestiltskin. In a Camelot flashback, Guinevere senses that Arthur is losing his way, consumed by his obsession with making Excalibur whole, so she sets out with Lancelot on her own quest into the heart of darkness. In Storybrooke, Dark Emma unleashes a secret weapon in the next phase of her plan to find the brave soul she needs to draw Excalibur from the stone.

Tensions in Camelot come to a head when Merlin, now under Arthur’s control, delivers an ultimatum to Emma: hand over the Dark One dagger and the Promethean spark or he will kill her entire family. Refusing to give in, Emma and our heroes face off against Arthur, Merlin and Zelena in an epic battle of magic and will. Just when the end is in sight, Emma is forced to make a gut-wrenching choice that no one saw coming. Back in Storybrooke, Zelena’s pregnancy mysteriously accelerates and Hook goes to new and desperate lengths to get answers from the Dark Swan.

In Underbrooke, Hook questions whether he is worthy of forgiveness after meeting his brother Liam. In the past, Liam makes a deal of his own to save himself and his brother... at the cost of a ship's worth of men. Meanwhile, Henry meets the Apprentice and learns of his true power.

Belle turns to Rumplestiltskin with hope of finding a way to protect their child from Hades. However, they disagree over whether to use dark magic, as Belle forbids Rumplestiltskin from using his powers for evil. Meanwhile, Hades secretly meets with Gaston in the Underworld and encourages him to seek revenge on Rumplestiltskin. As the heroes try to find a way to defeat Hades, Emma has a terrifying nightmare that she realizes is beginning to come true. And in flashbacks, Belle and Gaston meet for the first time, but their blossoming romance comes to a halt on the eve of the Ogre wars.

Emma, David, Regina, Robin and Henry are finally back home in Storybrooke and reunited with Snow, but, unfortunately, they still have to contend with Hades, who continues to deceive Zelena as he lays out his plan to use the all-powerful Olympian Crystal to take over the town. The heroes desperately search for a way to defeat Hades while Hook does the same in the Underworld, looking for those missing storybook pages. Regina and Robin take a more direct approach, which culminates in an epic showdown that will leave our heroes forever changed.

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.

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. 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.

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.

After Rumple's mother learns from his fairy godmother that his destiny is prophesized, she does everything in her power to keep it from happening. Meanwhile, in Storybrooke, Rumple faces a similar delimma.

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.

Rogers strikes a deal with Eloise despite Tilly’s fair warning, while Ivy struggles to find herself after Victoria’s death. Meanwhile, in a faraway realm, Hook confronts Captain Ahab over a legendary magical talisman which can free Alice, only to learn that his quest may have unintended consequences.

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.