Actors Ginnifer Goodwin And Josh Dallas, Right, From The TV series 'Once Upon A Time.'
Actors Ginnifer Goodwin and Josh Dallas (R) from the TV series "Once Upon A Time&" arrive at the 15th Annual Costume Designers Guild Awards in Beverly Hills February 19, 2013. Reuters

"Once Upon A Time" Season 4 spoilers have so far revealed a lot on what happens next in Storybrooke and the other realms in the ABC fantasy drama. Queen Elsa (Georgina Haig) of the 2013 Disney film "Frozen" is one of the most anticipated characters. She may or may not be the villain in the new chapter.

Spoiler alert: This feature contains spoilers on the new season of ABC's "Once Upon A Time." Season 4 premieres Sept.28.

"For the first time, we're showing a villainous side to Elizabeth Mitchell," executive producer Adam Horowitz told Entertainment Weekly in this report, hinting at a complicated Once Upon A Time Season 4.

The OUAT show bosses have earlier hinted that Queen Elsa could show her villainous side in Once Upon A Time Season 4. (Follow this link for a related OUAT 4 update.)

Mitchell, who joins Haig as an additional character in OUAT 4, is playing a dark character "connected both to the world of Arendelle and the world of Storybrooke," the OUAT showrunners revealed to EW.

"Thematically we can say the first half of the season is about how you never give up on the people you love," OUAT boss Edward Kitsis told EW.

In the past, Once Upon A Time showrunners Adam Horowitz and Edward Kitsis have gone on record to say those who saw the movie "Frozen" will see what happens next after the events in the film. This suggests the ABC TV series is not likely to alter the characters of Anna and Queen Elsa the way Peter Pan was reinvented in OUAT Season 3.

(Mitchell is the latest "Lost" alum to join the actors in Once Upon A Time.)

Mitchell's character could be relevant to the curse that was brought upon Queen Elsa, some OUAT fans point out in forum sites. Answers are expected to be explained throughout the first half of Once Upon A Time Season 4.

Toward the end of Once Upon A Time Season 3, Emma Swan (Jennifer Morrison) used her magic to travel through time. In doing so, she inadvertently took Marian, the wife of Robin Hood, to Storybrooke, and subsequently altered history.

As of the final act of OUAT 3, no one in Storybrooke is aware that Queen Elsa has gone through the same portal that Emma Swan has opened. The Evil Queen Regina, however, suspects things could get worse.

Once Upon A Time Season 4 premieres Sept. 28. Fans are looking forward to seeing what happens next to the complicated family of Snow White (Ginnifer Morrison) and Prince Charming (Josh Dallas), their daughter Emma Swan and newborn son Prince Neal.

To send feedback to the writer, e-mail a.paredes@ibtimes.com.au.