Once Upon A Time Winter Finale Sneak Preview Released

ABC has released a sneak preview of next Sunday's winter finale of Once Upon a Time: "Swan Song."

Darkness has descended on Storybrooke. As part of his plan for revenge, Hook opened the portal to the underworld and summoned all of the past Dark Ones. "You get to watch everyone you love die," Hook snarls at Emma. She fires back, "I will protect my family even if I have to kill you to do it."

Check out the trailer in the video below.

"Swan Song" episode of Once Upon a Time will air Sunday, December 6 at 8PM EST on ABC.