See the first sneak peek for Once Upon a Time‘s winter finale episode, “Queen of Hearts”! It’s a tense moment, after Regina and Gold have made a deadly decision.

In the video clip, we see Regina, Gold, Ruby and Henry by the well in the forest, where it seems like Gold and Regina are doing something to the portal to kill whatever comes through. Henry asks Regina, “You’re not helping Emma and Mary Margaret, are you?” Regina replies, “I’m helping you,” explaining that they have to prevent Cora coming through the portal at all costs – even if it means letting Henry’s mother and grandmother die.

“Good always destroys evil,” Henry insists, but Regina is unmovable. “What I know is that my mother will destroy everything I love. And that means you.” Henry keeps insisting that Emma and Mary Margaret will come through though, and implores Regina to have faith in him.

What is Henry planning to do? And is it really Emma and Mary Margaret who are trying to get through the portal, or Cora and Hook?!

The episode airs Sunday at 8/7c on ABC. It’s the last episode of Once Upon a Time until 2013, so it’s sure to leave us hanging with some epic cliffhanger… what will it be? Could it be that all the characters ended up back in Storybrooke – Emma, Mary Margaret, Aurora and Mulan, but also Hook and Cora?! We’ll have to wait and see.