'Once Upon a Time': Can Emma keep her powers under control?

The residents of Storybrooke may finally get a victory during Sunday’s episode of Once Upon a Time, when Emma (Jennifer Morrison) finally catches the elusive Snow Queen (Elizabeth Mitchell)—but all may not be what it seems.

“Elsa’s [Georgina Haig] working with Emma to try to focus her magic and try to use it more powerfully, and Emma is pushed to attempt that with the Snow Queen before she’s really ready,” Morrison tells EW. “It seems as if she succeeds at entrapping the Snow Queen, and brings her into the station to question her.”

But the interrogation takes a turn when the Snow Queen wages a bit of psychological war, using information about her former foster child’s past in a bid to get what she ultimately wants. “She knows how to push Emma’s buttons in a way that most people wouldn’t know. She knows those trigger points,” Morrison says. “She very carefully and craftily moves the conversation where she wants to move it and gets under Emma’s skin, which is what pushes her powers out of control the more that she’s stirred up internally. That’s exactly what the Snow Queen wants: She wants to stir up her powers, but we don’t know why initially.”

With Emma starting to lose control, those she loves most will find themselves in harm’s way. “She’s definitely uncomfortable with being out of control of her magic,” Morrison says. “It’s terrifying because she starts feeling like she could hurt people she really cares about and that’s the worst thing that could happen to Emma. She’s always putting everyone else first, and she’s far more concerned about the safety of people she cares about than her own safety.”

Henry, in particular, hopes to keep his mother in check, but may find himself in danger as a result. “She doesn’t want to do anything to cause him pain,” Morrison says. “He’s trying to help her, but in pushing her, she ends up being pushed out of control. The more he pushes, the more he puts himself in danger. It’s a terrible feeling to know that the person you truly love the most in your life in that moment is in the most danger around you. It makes her just want to get rid of her powers entirely. She’d rather not have any powers than have the possibility of hurting Henry or anyone else she cares about.”

Driving a wedge between Emma and her family is precisely what the Snow Queen wants, as the icy villain points out what the Savior has missed out on. “The Snow Queen does push her buttons about baby Neal, but it’s not in a way where she’s jealous or that she feels slighted by her parents in any way,” Morrison explains. “I felt it more come from a place of sadness and pain that she missed out on that with Henry, and that her parents missed out on that with her, and that was something they were never going to be able to reclaim. It feels tragic. The things that rile her up the most seem to come from a sadness of the things that have been lost and sacrificed, and the pain that she’s not dealing with in those sacrifices and those losses.”

Once Upon a Time airs Sundays at 8 p.m. ET on ABC.