David - aka John Doe - must choose between staying with Kathryn or leaving her to be with Mary Margaret, with whom he's fallen deeply, and inexplicably, in love; and Emma catches Sheriff Graham in a lie. Meanwhile, back in the fairytale world that was, Prince Charming is about to encounter a life-changing event that will forever alter his destiny.

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.

Mary Margaret hires Mr. Gold as her attorney when Emma is forced to arrest her for the suspected murder of David’s wife, Kathryn. Meanwhile, back in the fairytale land that was, Prince Charming sets out to stop a determined and unhinged Snow White, whose memory is still clouded by Rumplestiltskin’s potion, from assassinating the Evil Queen.

August tells Emma how to beat Regina and how she can get custody of Henry, while Regina hatches a plot to seduce David now that Mary Margaret is back at work. In the fairy-tale world, a plan to save Snow White and Prince Charming’s daughter unfolds and is agreed to by Geppetto, who has his own child’s safety in mind.

Emma and Mary Margaret try to find a portal that would bring them back to Storybrooke; Henry tries to talk Jefferson into reuniting with his daughter; on the eve of meeting Prince Charming's mother, King George poisons Snow White.

Ruby's fear about turning into a wolf is confirmed when she becomes the prime suspect for a vicious murder; Leroy finds treasure in a Storybrooke mine that could help Emma and Mary Margaret.

Mr. Gold tries to use an unwilling test subject to see if his spell works; Belle runs into vengeful Capt. Hook; David and Mary Margaret look for a bigger house.

David, Emma and Mr. Gold try to protect Mary Margaret from a vengeful Regina; a man and his son find their way into Storybrooke.

Mary Margaret, David and Emma embark on a search when Regina and some magic beans go missing; Mr. Gold considers revealing the truth to Lacey; Bae winds up in 19th century London.

Mr. Gold and Regina send Ariel back to Storybrooke with an item that will allow Belle to locate a hidden artifact that could help take down Pan. But unbeknownst to them, two men have broken into the town with the intent to stop them - at all costs. Meanwhile, Emma, Neal and Hook attempt to find Dark Hollow, where Peter Pan's shadow dwells, in order to capture it, and Mary Margaret is upset with David for keeping his poisoning a secret from her.

Pan's plan threatens the citizens of Storybrooke's joy over Henry's return; Snow and Charming spend their honeymoon searching for a mythical being that could stop Regina.

With Mary Margaret in labor and due to give birth at any moment, the residents of Storybrooke go on high alert in an attempt to ensure that Zelena doesn't try to steal her newborn baby for use in her ultimate game plan to turn back time and change her destiny -- while obliterating Regina's existence. Meanwhile, in the land of Oz of the past, Glinda tries to convince Zelena to fight her evil tendencies and join her and her sister witches as a protector of Oz. But the appearance of a young girl from Kansas could turn out to be her undoing.

Hook discovers that magic always comes with a price after he makes a deal with Mr. Gold to re-attach his hand so that he can embrace Emma with both hands on their first real date. And back in the fairy tale land of the past, Rumplestiltskin uses Anna to help him acquire a magical box from the sorcerer’s apprentice.

The race is on to track down the elusive Snow Queen in order to discover what her ultimate end game is for Elsa and the residents of Storybrooke. Unaware that she does not possess the real blade that controls The Dark One, Belle attempts to use it to get her reluctant husband to show her where the Snow Queen is hiding. Belle travels to Arendelle and, with Anna's help, seeks out Grand Pabbie to help her regain her lost memories in order to discover the fate of her mother.

David and Mary Margaret suspect Cruella and Ursula have come to Storybrooke looking for something more than their own happy endings – something that threatens to reveal a secret they thought was long buried. Emma begins her own investigation of Cruella and Ursula, but she can’t shake the feeling that her friends and family are keeping something from her. Regina and Henry continue their search for the Author, turning to Pinocchio and Marco in the hope Pinocchio might remember a clue that will help them. Meanwhile, in a flashback to Fairy Tale Land, Snow and Charming cross paths with the Queens of Darkness as the threat of the Evil Queen’s Dark Curse hangs over all of them.

Hook leverages his complicated history with Ursula to find out what she knows about Gold’s endgame. Gold and the Queens of Darkness torture August for information about the Author as Emma, Mary Margaret and David race to find them. Regina grows concerned for Robin Hood’s safety while she struggles to maintain her cover with the villains. In a Fairy Tale Land flashback, when a restless young Ursula enlists Hook’s help to run away from home, she soon learns it isn’t wise to trust a pirate.

Emma’s potential for darkness is looming over everyone, but when Emma realizes Maleficent’s daughter Lily is in fact her closest friend from her foster care days, she resolves to find Lily and reunite her with her mother. Regina joins forces with Emma and together they set out to track down Lily and to warn Robin about Zelena. However, neither of them is prepared for the harsh realities they’ll encounter in the outside world. Meanwhile, in Storybrooke, Gold faces a crisis involving Belle. In a foster care flashback, things are looking up for young Emma with her new family until Lily’s appearance threatens to destabilize everything.

In an effort to protect Emma, Regina steps up in a surprising way that will test her mettle as a force for good. King Arthur and Queen Guinevere throw a royal ball to welcome the heroes to Camelot, but when the celebration takes a deadly turn, David and Robin must leap into action or lose a crucial asset in the fight to save Emma. Back in Storybrooke, Hook deploys a tried-and-true technique in hopes of bringing Emma back to the light while the heroes discover that some unexpected baggage has followed them home from Camelot.

In a Camelot flashback, a chance encounter with Merlin, David, Hook and Belle gives Merida new hope in her quest to save her brothers from the usurping clans of DunBroch. Unwilling to leave anything up to fate, Merida brings Belle along on a dangerous journey that culminates with an invaluable lesson in bravery. In Storybrooke, Regina, Mary Margaret and David discover the spell that would allow one of Merlin’s chosen to communicate with him, but when Arthur fails to reach the missing sorcerer the heroes grow suspicious. Meanwhile, Emma commands Merida to kill Belle in hopes of forcing Mr. Gold’s heroic transformation. With Merida unable to disobey Emma’s orders.

Zelena and Arthur journey to DunBroch on a mission to retrieve an enchanted relic that will provide the advantage they need to vanquish Emma and our heroes. Their path will cross with Merida’s, who is on a journey of her own to pay a debt that her father, King Fergus, owed to the Witch when he died. Merida enlists the help of two friends, Mulan and Ruby, but, in order to satisfy the Witch and save DunBroch, she first must discover the identity of the knight who killed her father. In flashbacks, Merida learns about bravery and honor as she trains for combat and rides alongside Fergus into the infamous battle that claims his life.

The heroes join forces with an old friend of Snow's to defeat an obstacle standing in the way of finding Hook. Meanwhile, Hook encounters challenges of his own.

Regina reels from the death of Robin Hood, and everyone tries to give her room to grieve, but when the heroes discover Gold has stolen Hades’ Olympian Crystal and tethered all of Storybrooke’s magic to it, they set out to stop him. Henry decides he no longer can stand all the pain magic has caused his family, so he goes rogue, with Violet in tow, to destroy magic once and for all. Meanwhile, Zelena, Snow, David, and Hook attempt to open a portal that will return Merida and the other Storybrooke guests to their homes, but things go awry, and the group winds up in a deranged new world.