Evil Queen Regina Mills (Lana Parrilla) is likely to take centre stage in "Once Upon A Time" season 5 episode 2 titled "The Price". The sequel will revolve around the various challenges faced by the character as she tries to become the new saviour of Storybrooke and bring back Emma Swan (Jennifer Morrison) to light.

After several attempts to resist the darkness inside her, Morrison's character finally becomes the new Dark One towards the end of the premiere episode. The transition takes place after the heroes and villains go to Camelot accepting King Arthur's (Liam Garrigan) invitation.

While the cause for Emma's transition is yet to be revealed, the description of the upcoming sequel hints that Prince Charming aka David Nolan (Josh Dallas) and Robin Hood (Sean Maguire) could be the reason behind it.

The synopsis of episode 2 titled "The Price" read: "King Arthur and Queen Guinevere (Joana Metrass) 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".

So followers of the fairy tale series can expect a flash-back sequence that could explain the real reason behind a character change for Henry Mills' biological mother.

The sequel might also focus on the various efforts Parrilla's character will make to protect the protagonist. The summary states that the Evil Queen steps up in a surprising way that will test her mettle as a force for good.

Additionally, the synopsis indicates that the heroes will discover that an unexpected baggage has followed them home from Camelot. So speculations suggest that it might help them in recollecting the incident that lead to Emma's darkness.

Meanwhile, Captain Hook (Colin O'Donoghue) will deploy a tried-and-true technique in hopes of bringing back his ladylove to the light.

ABC will air "Once Upon A Time" season 5 episode 2 titled "The Price" at 8pm on Sunday, 4 October.

Watch the trailer below: