'Once Upon A Time' Season 4 Spoilers: Hook And Emma's Future, And Will Anna, Kristoff, And Olaf Of 'Frozen' Join The Cast?

As "Once Upon a Time" goes on hiatus until season 4, spoilers regarding Emma and Hook, as well as new potential characters.

Most fans know by now that "Once Upon a Time" season 4 will introduce Elsa from "Frozen," and many are wondering if others characters may join the fray.

“We would be very disappointed if Elsa was the only one from that world that you saw,” said co-creator Adam Horowitz to TV Guide. “Who else may appear, we're not ready to tell you just yet.”

Spoilers confirm that some characters in question include Elsa's sister Anna, her love interest Kristoff, and perhaps even Olaf. But will a snowman make its way to "Once Upon a Time" season 4?

"No comment," laughed Eddy Kitsis.

Fans who saw the "Once Upon a Time" season 3 finale also saw Hook and Emma kiss. But what does that mean for these characters in season 4?

“If you had said it to me when we first started the show, I never would have anticipated it — but the reality is that he’s a very kindred spirit,” said actress Jennifer Morrison to TVLine.

"They’ve both been through similar things, they’re both survivors and they’ve both had to fight in order to literally just live. There’s also something in them where they’ll both go to great lengths to protect the people they care about — and sometimes they’ll do really bad things to do that, but they both have really good hearts, so I think they see a lot of themselves in each other.”

Spoilers confirm that Morrison could see the start of a relationship between Hook and Emma, despite the recent passing of Neal.

“I know that in my own life, I have a strong reaction to people who empower me and say, ‘You should be yourself, even if it means making some mistakes.’ So the fact that he does that, and isn’t at all put off by that, makes it a good place to start a relationship.”