Once Upon A Time season 5 premiere live online: Watch Emma's transition from 'the saviour to the Dark Swan'

After being the savior for four seasons, Emma Swan will turn to the dark side in the fifth edition of Once Upon a Time that airs on Sunday 27 September at 8pm EST on ABC. Episode 1 is titled, The Dark Swan, where Amy Manson and Liam Garrigan guest star as Merida and King Arthur, respectively.

The synopsis of the premiere episode reads as follows:

Immediately after becoming the Dark One, Emma disappears and the heroes must band together to save her, but first they have to find her, which will require the help of an unlikely ally. Meanwhile, in the Enchanted Forest, Emma struggles to resist her dark urges as she searches for Merlin in the hope that he can stop her transformation. Along the way to Camelot, she gets help from the plucky and brave warrior princess Merida, as well as King Arthur and his Knights of the Round Table, in the adventure-filled season five premiere of 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. Meanwhile, Jennifer Morrison who plays Emma has said that Once Upon A Time's 5th season will pick up from where season 4 left off.

Morrison told Entertainment Weekly, "We pick up right where we leave off in terms of everyone in Storybrooke standing over the dagger and realizing that Emma sacrificed herself to save Regina's happy ending, and save the town, and save everyone.

"We pick up with them banding together and trying to figure out how they're going to find her, and what to do about it, and who's going to hold the dagger, because, obviously, that's a powerful position as well, and then we find Emma reborn as the Dark One somewhere," the actress added.

Although Emma will not immediately give in to Dark powers like Rumple, Morrison teased, "There's a similar journey for Emma, which is that once you've agreed to surrender to the Darkness and be the Dark One, that doesn't mean that you're consumed with it immediately. It means that it's within you, and now there is the struggle between what was once you and how to reconcile that with the Darkness that's also within you at this point."

"We're going to see her go through that struggle and that journey to fight within herself to make that decision," the 36-year-old added.