ABC's "Once Upon A Time" is set to return this Sunday night, Oct. 5, to continue the "Frozen" storyline and draw attention to the flashbacks that the show is using to tell the story of Elsa and Anna, who are being portrayed by Georgina Haig and Elizabeth Lail, respectively.

In the first episode of the season, the audience witnessed the sisters in Arendelle, although Anna is expected to venture out to the Enchanted Forest in episode two.

Entitled "White Out," Anna will be helping out David (Josh Dallas) in fighting Bo Peep (Robin Weigert), although the show's take on Bo Peep is very different from the fairytale's. In a sense, the character can be considered as a "brutal warlord."

Meanwhile, Elsa will be meeting the people of Storybrooke but will get herself trapped with Emma (Jennifer Morrison) in an ice cave. While Elsa's powers are likely to have adverse effects on Emma, the two will somehow form a strong bond with which Elsa will also assist Emma in controlling her own magic.

"The crisis in the ice cave, combined with the many similarities that they share, makes Elsa and Emma fast friends," Morrison explained to TV Line. "Emma realizes quite quickly that Elsa is misunderstood and is just trying to get her sister back and get her powers under control."

Furthermore, the actress also stated how the two characters will begin responding well to their current situation.

"They start dealing with how complicated [their] situation is," Morrison said. "It's not like they 'duke it out,' and it's not like they talk it out, but they start dealing with it."

Elsa's powers, however, have been deemed a nuisance by Storybrooke residents. With frozen and broken power lines, the town is expected to look for someone who they can trust to address Storybrooke's current problems, such as Mary Margaret (Ginnifer Goodwin).

In addition, Evil Queen Regina (Lana Parrilla) will be going into a severe bout of depression after splitting up with Robin Hood (Sean Maguire).

The second episode of "Once Upon A Time" season four will air on ABC this Sunday, Oct. 5, at 8 p.m.

Here is the official promo for the second episode: