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.

When Mary Margaret learns of Cora and Regina's plan for the dagger, she resolves to find it first; Mr. Gold continues his search for Bae; the Blue Fairy offers Snow White an enchantment to save her mother.

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.

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.

As Storybrooke descends into chaos as the Snow Queen's spell takes hold, Emma and Elsa try to trick Regina into destroying the ribbons so that they can attack the Queen. In the past, Ingrid adopts Emma and attempts to show the girl that she's a powerful sorceress.

The dark siege of Storybrooke is underway as all of the resurrected Dark Ones target a living soul for sacrifice so that they can return to the realm of the living. With doom imminent, Gold advises Mary Margaret, David and the rest of the heroes to spend their last fleeting moments enjoying the company of their loved ones. Emma, however, refuses to give up, knowing that she is responsible for righting all the poor choices she made as Dark One - there's only one problem, Dark Hook. When they face-off with the fate of Storybrooke at stake, Hook's actions will devastate Emma in a way no one saw coming. In a Fairy Tale Land flashback, the Evil Queen tests Hook's mettle by forcing him to confront a demon from his past before contracting him to dispatch one from hers.