There has been a hint that Elizabeth Mitchell will be seen in Season 4 of "Once Upon a Time," although her role is not yet known.

Inquisitr reported that showrunner Adam Horowitz said he is excited with the actress' appearance on the show and teased the audience over what role she will be playing.

Season 4 of "Once Upon a Time" will air on Sept. 28. According to IB Times, there are rumors suggesting that she will be playing the role of a villain, since there is no antagonist in the show. On the other hand, the villain in "Frozen" is Elsa. Still, there is still no confirmation if the character Mitchell will play will be a sinister one.

Season 4 will feature the story of Frozen, as in the movie. It was previously revealed that Queen Elsa will be reverting to the original role as the villain in the Snow Queen story. However, the TV series had been twisting the fairy tales' original characters and making them into villains. It is now confirmed that the Disney movie storyline will be followed by the TV version, The Hollywood Reporter reports.

The first episode will probably feature the two sisters, Anna and Elsa, since it is titled "A Tale of Two Sisters." It is also possible that their back story will be the same as that shown in the movie version and possibly expand to show how they ended up in Storybrooke.

Anna, Elsa and Kristoff are confirmed to be in Season 4 together. In the trailer, Storybrooke had an icy makeover and showed the reaction of the residents to the arrival of the newcomers.

Elsa was shown walking in the town center with a trail of ice. Watching from his window, Rumpelstiltskin was surprised by the arrival of Elsa. Snow White and Prince Charming, armed with bow and arrow and a sword, jumped from behind a car and Hook did not look pleased that his hook hand was frozen. Outside of Granny's restaurant, Emma and the Evil Queen were watching Elsa.

Fans of the show will learn more about Elsa's past, how she came to be in the dungeon of Rumpelstiltskin, and what her plans will be while she's in Storybrooke. Catch up with the trailers at ABC.