"Once Upon a Time" season 5 is all set to air its winter finale episode 11 titled "Swan Song". And, it is expected that the story arc will be really dark. There have been various speculations about how Hook may die in the winter finale and if Underworld will be introduced in the upcoming episode.

CLICK HERE to watch "Once Upon A Time" Season 5 Episode 11, titled "Swan Song", live online. You can CLICK HERE to watch it later online.

Last week in episode 10, we saw the worst side of Hook, who is the second Dark One. He manages to get through his plan of resurrecting all previous Dark Ones, including Nimue. And finally, we got to know what Emma plans to do next.

The episode, titled "Broken Heart", witnessed how Hook gets on the path to seek revenge from Rumplestiltskin, a man he holds responsible for his life-long pain. On the other hand, Emma was seen attempting to stop him and when she fails, she teams up with Henry to stop Hook's Dark One.

Meanwhile, the episode also threw light on Rumple and Belle's relationship problems and how Zelena adapted to a skewed motherhood.

In the upcoming episode 11, Hook, Nimue and all the former Dark Ones will enter the town to target living souls for sacrifice. But the promo teases that Emma will threaten to kill Hook if that's what it takes to save lives of other family members. Another angle that fans are expecting to see in episode 11 is about the side Zelena will choose to save her daughter.

According to Christian Post, the winter finale will set the stage for the second half of season 5 and the characters will get to explore the afterlife in Once Upon a Time season 5B.

Official plot synopsis of Swan Song reads: "The dark siege of Storybrooke is underway as all of the resurrected Dark Ones target a living soul for sacrifice so that they can return to the realm of the living. With doom imminent, Gold advises Mary Margaret, David and the rest of the heroes to spend their last fleeting moments enjoying the company of their loved ones. Emma, however, refuses to give up, knowing that she is responsible for righting all the poor choices she made as Dark One – there's only one problem, Dark Hook."

"Once Upon A Time" Season 5 Episode 11, titled "Swan Song", will air on ABC on Sunday, 6 December, at 8 pm.