See what the Once Upon a Time creators can reveal about the fast-approaching season 4: will Elsa and Anna be friends? What will happen with Regina and Robin? Find out here!

The Once Upon a Time season 4 premiere is only 10 days away! “A Tale of Two Sisters” will see Elsa of Frozen fame (played by Georgina Haig) wreck havoc on Storybrooke.

But it won’t be all bad, according to Edward Kitsis and Adam Horowitz. The pair have made the media rounds this week, talking to TV Fanatic and The Hollywood Reporter about what’s coming up.

Kitsis reveals to TV Fanatic that in fact, “Elsa and Emma are going to have a friendship that we’re going to see play out.” The two characters have a lot in common, and this is going to bond them together.

“What happens when Elsa, who is somebody who wanted to run away, meets another character who loves to run away, Emma?” Kitsis teases.

Speaking to THR, Horowitz further reveals that the Frozen characters will be a mystery to most of the Storybrooke characters, as in fact the timeline puts us in early 2013 – before Frozen had been released! So, “None of the present-day Storybooke characters are aware of the Frozen mythology and universe.”

“When Elsa arrives, it signifies the start of a mystery that needs to be explored and answered,” Horowitz says. “And the repercussions of that mystery reach out and touch everyone, and you’ll see it affects everyone from Regina to Emma to Rumpelstiltskin.”

But while Frozen will be a huge part of the first block of season 4 episodes, the writers haven’t forgotten about the pre-existing storylines.

“We are going to be turning Frozen, but not at the expense of the other stories,” Kitsis promises. “So Once fans who think that Frozen is going to take over can relax.”

One of the most intriguing storylines is the Regina/Robin/Marian love triangle, which Emma inadvertently set in motion when she saved Marian’s life.

Related: Once Upon a Time season 4 promo: Regina’s new agenda

Luckily, the writers aren’t going to use this as an excuse to bring back evil!Queen Regina.

“She’s not going to revert to what she once was,” Horowitz promises, “because people don’t generally do that. But… the Evil Queen part of herself is something that she’s going to have to kind of wrestle with, as she deals with a huge blow to what was a glowing moment.”

She is going to have something different occupying her mind, however. “Regina is also going to be launched on a new quest with Henry this year,” Horowitz reveals. “We’ve seen Henry in Operation Cobra with Emma, but we’re going to see a new one with Regina that we’re very excited about.”

As for Marian, she’s not going to adjust to the situation very easily. “She’s really disoriented in trying to get a handle on everything,” Kitsis says. “It’s one thing to find out your husband thought you were dead and moved on. It’s another when you find he moved on with the person who killed you.”

Once Upon a Time season 4 will also dig deeper into Belle’s backstory, introducing her mother. “We’re going to see where Belle got the idea of wanting to be a hero,” Kitsis teases, adding that we can expect Rumpelstiltskin’s big deception (with the fake knife) to be addressed very soon.

One of the most exciting things about season 4 is the introduction of Michael Socha, the Knave from Once Upon a Time in Wonderland. But don’t expect too much too fast!

Related: Once Upon a Time season 4: First 6 episode titles revealed

Kitsis says that while, “we’re going to get a little taste of Michael in the first 11 [episodes],” a lot of his story will be told in the second half of the season.

The Knave is a disgraced member of Robin Hood’s band of Merry Men, and he’s got a whole post-Wonderland arc which needs to be explained, so fans of both shows will understand what brings him to Storybrooke.

“We’re also going to find out that he has an interesting connection to another character from the past, from season 1 of Storybrooke,” Kitsis says.

Finally, the writers reveal that the second episode of the season, “White Out,” will be a Charming-centric flashback, showing him meeting Snow White when he was still a shepherd.

Once Upon a Time season 4, episode 1 “A Tale of Two Sisters” airs Sunday, September 28 at 8/7c!