The synopsis for Season 4 of Once Upon a Time essentially indicates that Frozen's Queen Elsa (Georgina Haig) will be the season's villain.

Once Upon a Time's Belle "Going To Find Out About That Dagger" In Season 4

A short synopsis for the upcoming fourth season of Once Upon a Time was released, per SpoilerTV, and it seems that Elsa may become the latest villain after the Wicked Witch/Zelena (Rebecca Mader) and Peter Pan (Robbie Kay).

"Master storytellers Edward Kitsis and Adam Horowitz (Lost, Tron: Legacy) invite everyone to join Emma Swan [Jennifer Morrison], Snow White [Ginnifer Goodwin], Prince Charming [Josh Dallas] The Evil Queen [Lana Parrilla], Hook [Colin O'Donoghue] and all the other resident fairy tale characters as they prepare to defend themselves against a magical force from the past that's too dark and unpredictable even for Rumplestiltskin [Robert Carlyle] - The Ice Queen."

Sidney Glass/Magic Mirror Returning For Season 4 of Once Upon a Time

It is not immediately clear if the synopsis is referring to Elsa with the "Ice Queen" mention, but with all the hype surrounding Frozen on Once Upon a Time, it seems likely. It is also possible that recently cast Elizabeth Mitchell could be playing The Ice Queen, though there are no details surrounding her character other than the news that she has a connection with Elsa and Anna (Elizabeth Lail).

Haig is expected to make her big Once Upon a Time debut as Elsa in the Season 4 premiere, titled A Tale of Two Sisters.

Once Upon a Time Season 4 is expected to return in the fall on ABC, though the network has not yet announced a specific premiere date. It will be returning to its regular Sundays at 8 p.m. timeslot.