"Once Upon A Time" season 4 spoilers are here and the show will explore the story behind Arendelle, particularly Queen Elsa and Princess Anna's parents. The series will also jump in and out of the 'Frozen' timeline.

Natalie Abrams of TVGuide revealed "Once Upon A Time" spoilers when she said that the parents of Queen Elsa and Princess Anna will be highlighted as the season rolls along, after talking to executive producer Edward Kitsis.

"There may be some things with the parents we didn't know about pre-Arendelle," the showrunner said.

"As for present-day Storybrooke, it's pretty obvious that, with Elsa in her Frozen duds, her escape from the urn comes after the movie," Natalie Abrams wrote.

This was confirmed by Adam Horowtiz who said: "What happened to her to get her into that urn and what was going on in her life at that point is what's going to be revealed and what's going to be pushing the story forward."

Horowitz added that they are going to reveal some things hoping that fans will see some "surprising connections between Arendelle and our world."

Earlier, Michael Ausiello dished out "Once Upon A Time" season 4 spoilers when he revealed the interesting casting call made by ABC.

"For Season 4's fourth episode, the ABC series is casting the role of an elderly, grizzled and unflappable knight who for many, many years has dedicated himself to serving a righteous cause. Anyone else getting a Holy Grail vibe from this...?" he wrote.

Adam Horowitz revealed on Twitter that episode 1 will carry the title "A Tale of Two Sisters," which could refer to Queen Elsa and Princess Ana if the series will follow the "Frozen" story arc.

An image was also posted on his social media account showing episode 2 with the title "White Out," along with the caption: "Here's another #OnceUponATime #titlespoiler Hope to see ya 9/28 for Season 4!"

Episode 3, meanwhile, will be called "Rocky Road," which could suggest a new challenge for the main characters.