Once Upon a Time season 5
Emma gives in to her dark side in OUAT season 5ABC

The concept of heroes and villains has witnessed a sea-change in Once Upon a Time's 5th season as Emma now has become the Dark One aka Dark Swan and Regina aka the evil Queen has become a saviour for the Storybrooke folks. Episode 2 is titled, The Price, which will air on Sunday, 4 October at 8pm EST on ABC Network.

The official synopsis reads as follows:

In an effort to protect Emma, Regina steps up in a surprising way that will test her mettle as a force for good. King Arthur and Queen Guinevere throw a royal ball to welcome the heroes to Camelot, but when the celebration takes a deadly turn, David and Robin must leap into action or lose a crucial asset in the fight to save Emma. Back in Storybrooke, Hook deploys a tried-and-true technique in hopes of bringing Emma back to the light while the heroes discover that some unexpected baggage has followed them home from Camelot, on Once Upon a Time.

Click here to watch the episode via live stream online on ABC, or click here to watch it online on ABC's official website.

The premiere episode opened with Emma struggling with her dark powers as Hook, Snow, Charming and Regina travel to Camelot to help her. But the episode ended with a six-week flash-forward and all the heroes are back from Camelot, but they don't remember what happened in that time period. Also, Emma embraced her dark side and is hellbent on revenge.

Once Upon a Time bosses Adam Horowitz and Eddy Kitsis previewed what to expect next in season 5 and teased the "missing memories" part will be shown in flashbacks.

Kitsis told Variety: "We are going to be flashing back to Camelot and then present-day Storybrooke, with a few origin stories," including backstories for Merlin, Arthur, Guinevere, Lancelot and Merida.

However, Horowitz promised that "it's not gonna be the whole winter before we catch up [with what happened during those six weeks], and it's not necessarily everybody at the same time".

Despite the introduction of several new characters in Camelot, Horowitz insisted that the story will focus on "our core group of characters and what they're going through in Camelot with regards to Emma... We'll see what seems to have happened to her and [explore] that mystery and how they can or can't help her."

A new promo shows Emma telling Regina that new trouble awaits the town. Now that Emma has turned dark can Regina step into her shoes in episode 2? We will have to wait and watch.

There’s a problem headed to Storybrooke that only a savior can solve…#OnceUponATime is all-new Sunday at 8|7c.

Posted by Once Upon a Time on Friday, 2 October 2015