"Once Upon a Time" Season 5 is back after a brief break since it last aired Episode 9, "The Bear King", on 15 November. The season so far has been all about stopping the bad "ones" and the trend will continue is Episode 10, where Hook will take on to the dark side and Emma Swan will have to bear the consequences of turning him dark.

CLICK HERE to watch "Once Upon A Time" Season 5 Episode 10, titled "Broken Heart", live online. You can CLICK HERE to watch it later online.

In Episode 9, titled "The Bear King", we saw Merida making a comeback as she stood on King Fergus' grave and is to be crowned the queen. But then, we are taken back two years, where Fergus is seen visiting the local witch and requesting a magic helm to wear into battle. And when we return to the present day, Merida's crowning is interrupted by the same witch, who is now demanding the price for magicking the helm.

Merida then decides to find her father's killer in order to track down the helm, and in the quest she recruits Mulan and Red. When they reach the helm, they are met with opposition from Arthur and Zelena, whom they and members of the clans overpower. But at the end of episode, the witch explains the helm had no magic and the journey was to test Merida's leadership. She is finally crowned queen and she vows revenge on Arthur, who slayed her father.

In this Sunday's Episode 10, we will see Emma facing the consequences of turning Hook dark as he tries to hurt her. Their relationship will be put to test and Hook will be seen taking out his new-found evil on Emma. The promo of "Broken Heart" teases Hook still wanting to take his revenge on Rumplestiltskin. He will focus on centuries of anger on Mr Gold, while Emma tries to get her love to move out of the dark side.

The synopsis of "Broken Heart" reads: "In a Camelot flashback, Hook becomes a Dark One and his lust for revenge against Rumplestiltskin is reignited. When Emma and Hook disagree about their best course of action, the final pieces of the puzzle are revealed as events in Camelot catch up to the present and we witness a charged confrontation between the forces of light and dark that sends our heroes on a collision course with destiny."

"Once Upon A Time" Season 5 Episode 10, titled "Broken Heart", will air on ABC on Sunday, 29 November, at 8 pm.