Hold on tightly, Once Upon a Time fans: as teased by Jennifer Morrison, this Sunday's winter finale promises to conclude with an intense cliffhanger.

It's not difficult to imagine how, following the events on last night's "Into the Deep," which focuses on Henry and Aurora's shared dreams, along with Cora's dastardly, desperate actions.

Look for this villain to team up with Hook on "Queen of Hearts," while Regina and Mr. Gold also join forces to prevent her from finding Storybrooke. But will their magical scheme place Emma and Mary Margaret in danger?

Watch the official ABC teaser for the final episode of 2012 now:

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