ABC has put most of their promotional material for Season 4 of Once Upon a Time behind the inclusion of Frozen, but that doesn't mean the series' main characters will be ignored.

Hook Continues "Very Complicated" Relationship With Emma When Once Upon a Time Returns

Once Upon a Time co-creator Adam Horowitz spoke with Entertainment Weekly in a new Friday report, revealing that much about Emma (Jennifer Morrison) and her past will be revealed in Season 4.

"In the first half of the season, we're going to see more of Emma's past than I think we've seen in all the other previous seasons combined," Horowitz revealed.

Frozen Characters Anna & Kristoff Preparing For Their Wedding on Once Upon a Time

Emma has had her fair share of flashbacks over the course of Once Upon a Time, but it seems that there is still much to learn about the scrappy character. She was last seen returning from the past with Hook (Colin O'Donoghue), her newfound love interest.

In the mean time, it is going to be a Frozen invasion on Once Upon a Time next season as characters from the massively successful animated film are introduced in live action. Elsa, who will be played by Georgina Haig on the series, is featured prominently on a new poster for Once Upon a Time Season 4 released Friday, posted via SpoilerTV.

The poster shows Elsa from behind wearing her iconic blue dress and sporting her blonde braid. She is using her icy powers and causing the Once Upon a Time logo to appear icy blue.

The tagline appears above the logo, reading, "Storybrooke has frozen over."

Elsa will enter Storybrooke in the Season 4 premiere and create a "powerful snow monster" in order to protect herself from the unknown forces surrounding her.

Once Upon a Time is set to debut its fourth season Sunday, Sept. 28 at 8 p.m. ET/PT on ABC.

Tags: Once Upon A Time television ABC