Belle's mother died when their castle was attacked by ogres but Belle lost all memory of the event. Against her father's wishes, she heads to Arendelle believing the trolls there can help her retrieve her memories.
In the past, Anna comes back to Arendelle and finds Elsa training to control her powers with the Snow Queen who says she's Ingrid, their aunt. Anna tells Kristoff she doesn't trust Ingrid, the Snow Queen overhears.
Anna doesn't share with Elsa that she learned her parents planned to strip her of her powers. She runs into Belle and brings her to the rock trolls. GranPappy gives Belle a rock with her memories. If she brews it in a tea and drink it, her memories will return. He tells Anna that her mother, Gerta had two sisters, Ingrid and Helga who vanished. Their parents asked that all memory and mention of them be erased.
Before Anna can get back to tell Elsa, the Snow Queen conjures a storm. It leaves Anna dangling from a cliff. Belle tries to retrieve her rock which she's dropped before she helps Anna. The rock fallls and shatters and then Anna falls. As she lies unconscious, the Snow Queen magically takes her and the sorcerer's hat she holds.
In current day Storybrooke, Emma shows everyone the video of her and the Snow Queen from when she was a teenager. They all hunt for the Snow Queen's ice cream truck. When they find it they discover a file filled with clippings of Emma going back to her as a baby being found in this world.
Belle and Elsa work together at the library to try and track down the Snow Queen. Belle lies and tells Belle she doesn't know Arendelle or Anna.
Belle tells Rumple she needs his help finding the Snow Queen. When he refuses to help her, saying it's too dangerous, she pulls out the dagger to force him to help, not knowing it's a fake but Rumple plays along.
When Belle finds the Snow Queen's cave, her magic mirror turns on her making her believe all that is dark, that Belle is nothing but a coward, that Rumple doesn't love her and that he's lying to her about the dagger. Shaken up, Belle tells Rumple the truth about Anna and the sorcerer's hat.
Belle confesses to Elsa all that happened in the past. Elsa finds a family tree in the library that lists her mother's sisters. There's also a scroll in the Snow Queen's file which says she must find the savior, Emma and that she will be her new sister. Rumple says if the Snow Queen performs a spell with the mirror, she will turn everyone in Storybrooke against one another, destroying the town and leaving Elsa and Emma as the only two left as the family she desires.
Regain tells Robin that she doesn't believe she break the spell on Marian. The only way to do it may be if Robin falls back in love with her and gives her true loves kiss.