Witch Hunt

"Witch Hunt" is the thirteenth episode of the third season of Once Upon a Time, and the show's 57th episode overall, which aired on March 16, 2014.

Synopsis
Emma arrives in Storybrooke with Henry, only to discover that no one remembers how they were transported back – or the past year they had spent back in fairy tale land. Emma teams up with Regina in an attempt to uncover who created the new curse. Meanwhile, in the fairy tale land that was during the past year, Regina, with the aid of Robin Hood, attempts to break into her castle, which has been overtaken by the Wicked Witch.