Plot summary
In Storybrooke, the mysterious Snow Queen—whose public identity is that of the owner of an ice cream shop—frame Elsa for putting a freezing spell on Marian to have the Storybrooke residents cast doubts on her. When David and Emma encounter Will Scarlet, they find out about the Snow Queen, only to discover that the Snow Queen knows Emma from a past encounter that Emma doesn't remember, though Mr. Gold does. Henry helps Regina track down the author of the Once Upon a Time book, and Hook believes Gold is still in possession of the real Dagger. Back in Arendelle of the past, Elsa and Kristoff must fend off Hans, who is plotting another attempt to take over Arendelle, only to unwittingly unleash the Snow Queen, who freezes him. She reveals herself as Elsa's aunt.
Credits
Adapted from Wikipedia contributors, Once Upon a Time season 4. HTML formatting and reference markers removed.