Jennifer Morrison said that the events of the fantasy drama's first season finale will have long-reaching consequences.
Watch the Once Upon a Time cast discuss season two below: (Spoilers for UK viewers)
"Now that everybody has found out who they really are, there's going to be a lot of emotional repercussions," Morrison, who plays Emma Swan, explained.
New series regular Meghan Ory (Red Riding Hood / Ruby) agreed: "Everything is going to change so much once people have memories that are not their own, of lives they didn't know that they had. They've woken up in a foreign land, basically."
Fellow Once star Ginnifer Goodwin also promised that the relationship between Snow White and Prince Charming (Josh Dallas) will be "titillating".
"I think it's going to be as satisfying and frustrating as it was last season, but for totally different reasons!" she teased.
Goodwin added of the new episodes: "We have no idea what magic in Storybrooke means, we have no idea if it operates by the same rules. It's kind of a whole new world."
Once Upon a Time returns to ABC this fall. In the UK, the series airs on Channel 5.