Once Upon a Time Creators Tease "Close-Ended" Frozen Story, Elizabeth Mitchell Character

Let's just get the sad news out of the way first:

Olaf will NOT be coming to Once Upon a Time Season 4.

Executive Producers producers Edward Kitsis and Adam Horowitz made this clear in a chat with EW this week, also shooting down talk of casting Sven because, well, he's a reindeer.

But we do know that Frozen characters Elsa (Georgina Haig), Anna (Elizabeth Lail) and Kristoff (Scott Michael Foster) will play key roles on the ABC drama this fall, starting with the premiere, which will be titled "A Tale of Two Sisters."

Expect to see these new characters often… but for a limited time. Similar to last year’s Neverland arc and Wicked Witch arc, Horowitz confirmed this will be a “close-ended story.”

It will cover the first half of Season 4.

As for what we can expect from Haig's Elsa?

"What we love about Elsa is that she is uncomfortable with her power, she’s lonely, but wasn’t quite sure how to break that loneliness - it took the love of her sister," Kitsis says. "So we’re not interested in Elsa meeting someone, we’re interested in exploring her as a person, like we have with Regina the past few years."

So, no, Horowitz joked: Elsa will not be going on Match.com. The relationship between siblings will be "central" to the OUAT story.

The creators did not touch on rumors of a Frozen-themed Once Upon a Time spinoff, but they did give strong hints about Elizabeth Mitchell's character.

The beloved Lost/Revolution actress will appear on multiple upcoming episodes, as either Anna’s mom (who survived that sea voyage) or the original Snow Queen.

"We’ll find Elizabeth Mitchell’s character is connected both to the world of Arendelle and the world of Storybrooke," teased Horowitz.

Visit EW now for plenty more from the Once Upon a Time creators and sound off: Are you excited for Frozen to meet Storybrooke?!?