Regina does everything in her power to force Emma out of Storybrooke and out of her and Henry's lives forever. Meanwhile, the chilling circumstances of how the Evil Queen released the curse upon the fairytale world is revealed.

One of the town's residents begins to remember their fairytale past, and Storybrooke mourns the loss of one of their own. Meanwhile, in the fairytale world that was, the Evil Queen attempts to find a heartless assassin to murder Snow White.

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.

A dejected Sidney enlists the aid of Emma to help uncover evidence that could expose Mayor Regina as the corrupt person she really is to the townspeople of Storybrooke. Mary Margaret and David continue their secret rendezvous while trying to figure out a way to unleash their forbidden love. Meanwhile, back in the fairytale land that was, King Leopold, who is the father of Snow White and married to the Evil Queen, stumbles upon a magic lamp and is granted three wishes by a Genie - who warns the king to be careful what he wishes for.

Unlikely allies Mary Margaret and Leroy team together for a good cause to help the Storybrooke nuns sell their candles during the town's Miner's Day festival. But Leroy makes a promise to a nun, Astrid, that he may not be able to keep; and Emma looks into the mysterious disappearance of David's wife, Kathryn. Meanwhile, in the fairytale land that was, Grumpy finds forbidden love with beautiful but clumsy fairy Nova.

While searching for a missing Mary Margaret, Emma is kidnapped by a man whose affinity for hats has him teetering on the edge of madness. Meanwhile, viewers will be transported outside of the fairytale land that was for the first time when the Evil Queen persuades a skillful man of magic to come work for her one last time and travel to Wonderland in order to help steal something from the Queen of Hearts.

Emma continues her exhaustive search for evidence that will prove Mary Margaret's innocence in the murder of David's wife, Kathryn. Meanwhile, in the fairytale land that was and before evil blackened her soul, Regina must choose between betraying her mother, Cora, and marrying for true love, or betrothing royalty and living a regal - but loveless - life; and the event that caused the Evil Queen to loathe Snow White is revealed.

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.

While Emma, Mary Margaret, David, Regina and Hook continue their search for Henry in Neverland, Peter Pan appears before a startled Emma and offers her a map that will reveal her son’s whereabouts. But the only way to make the map appear is for Emma to stop denying who she really is and come to grips with her true feelings about her identity – and Mr. Gold receives some unexpected advice from a friend that could lead him to understand his life’s journey while in Neverland. Meanwhile, in the Fairy Tale Land that was, when the Evil Queen presents Snow White with an offer to live her life with Charming in peace – with the caveat that she give up her claim to the throne – Charming makes it his mission to ensure that Snow doesn’t take the offer.

The race to stop Pan is on as Henry's life hangs in the balance; with Mr. Gold's help, Regina decides to adopt a baby.

A scared and confused Elsa from Arendelle finds herself in Storybrooke and creates a powerful snow monster for protection. Regina wonders if her relationship with Robin Hood has been completely quashed now that Marian's back in the picture. Elsa's sister wants to complete their parent's fateful journey and discover if their quest may have held the secret to containing Elsa's out of control ice powers.

Emma tries to convince a reluctant Regina to help her find the Snow Queen, only to discover that Regina is lying to her about Sidney's whereabouts. Meanwhile, David convinces Mary Margaret to go on a date, but the date turns into a hunt when Will escapes his jail cell. In the past, Emma befriends another young orphan who isn't all that she seems.

Emma, Regina, Mary Margaret, David, Robin, Henry and Gold arrive in the Underworld, on a mission to rescue Hook, only to discover that their search will be more difficult than they had anticipated. The inhabitants of the Underworld — all souls with unfinished business and many with quite personal vendettas — hound our heroes at every turn. Meanwhile, in an Enchanted Forest flashback, a familiar face from the Evil Queen’s past returns to present Regina with the perfect birthday gift.

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.