Jared Gilmore, Jennifer Morrison

The evil smoke monster curse is back once again in the season finale of Once Upon a Time!

Sunday's finale, "A Land Without Magic" (8/7c, ABC), brings the series full circle from when the Evil Queen (Lana Parrilla) unleashed the curse that enslaved every fairy tale character in the town of Storybrooke, forced to live unaware of their true identities. Now, Emma (Jennifer Morrison) must decide whether or not she believes, which will then determine the fate of her son, Henry (Jared Gilmore), who ate the poisonous fruit that was meant to kill Emma.

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Will Emma realize the truth before it's too late? TVGuide.com turned to executive producers Adam Hororwitz and Edward Kitsis to get the scoop on the finale, including who is the most heroic in Storybrooke, the many returning faces and whether Emma will ultimately sacrifice herself to save the trapped fairy tale characters.

What can you tell us of Emma's struggle to really believe in the finale?
Adam Horowitz:
The stakes have never been higher for what she's dealing with, which is Henry. She's from this world, and what she's being asked to believe by Henry, it's a pretty monumental leap for anyone to make.
Edward Kitsis:
And that was something that we really wanted to do, which was really earn her journey. Such as, the first time she is told this information, like anyone, she thinks it's crazy. What we love is that when August (Eion Bailey) is yelling at her, "Why won't you believe?" we know he was not only speaking for himself, but for the audience. For us, it is important that the day that Emma does believe, we feel like we've earned it, as opposed to, it's Episode 2 and now she believes and she is fighting sea monsters.

Will Henry's ailment be the catalyst for her to finally believe?
Kitsis: What I love is that Henry, basically in a lot of ways, is the most heroic because he sacrificed his life to get her to embrace her destiny. We will see if it was done in vain, but we've tried everything else. We tried to show her a wooden leg, we've tried to show her time moving, we've tried to show her all these things and she hasn't believed. So this was it. This is the last chance.

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How will Regina and Emma have to team up in the finale because of Henry? And how will the curse ultimately backfire on her?
Horowitz:
Regina has enjoyed an uninterrupted reign of 28 years that has now slowly been getting more and more intensely difficult. In the finale, the challenges she faces to her place in Storybrooke and her power are greater than she has ever faced. But she is a formidable foe, so she's ready to rise to that challenge.

It's interesting that we learned that if Emma dies — or maybe it's only if Regina murders her — then the curse is broken. Would Emma ever consider sacrificing herself just to break the curse?
Kitsis:
Her first step would be to believe in it. I absolutely believe Emma would sacrifice herself because I think that's the kind of person she is, but we'll have to keep watching the show and see what happens.

Going over to fairy tale land, Charming (Josh Dallas) and Snow (Ginnifer Goodwin) have been desperately trying to reunite, but now Snow has eaten the famed poison apple. What can you tell us about the finale for them?
Kitsis:
If last week was Snow's side of it, this week will be Charming's. We hope that this fairy tale flashback will fill in some holes that we've seen through the year, but will also, hopefully, raise some new avenues for next season

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There are plenty of returning faces in the finale — Belle (Emilie de Ravin), Maleficent (Kristin Bauer van Straten), the Huntsman (Jamie Dornan) and the Mad Hatter (Sebastian Stan), among them. Is there anything you can tease about their returns?
Kitsis: I would say that you never know where you'll see them. It is a finale, after all.

How about at least something for the Huntsman fans. They're dying to see Jamie again!
Kitsis:
He is oddly more handsome now then he was when you last saw him. He's actually extra handsome. How we reveal the Huntsman is one of our favorite things ever, so we don't want to spoil it because it's oddly one of the things we've been able to keep secret. We're excited to see Jaime come back, and he's fantastic.

How will Mr. Gold (Robert Carlyle) feel if he finds out that Regina has been keeping Belle trapped in a mental ward?
Kitsis:
I can't image that if Mr. Gold was told that not only was Belle not dead, but that he was lied to and she's been imprisoned for all this time, I would start running.

Can we look forward to a confrontation in that regard?
Kitsis:
In the finale, we endeavor to satisfy some of the things we've set up this year. As a fan, I would be completely annoyed if we saw at the end of Episode 12 that she was locked in an insane asylum and we don't return to that. I would throw something at the screen.

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The veil between the two worlds actually seems to be getting thinner. Could we ever see them collide? Or see another vortex?
Kitsis:
I think the two worlds tend to collide every week. Will they actually merge into one thing? I don't know.
Horowitz:
We saw Jefferson reach across time and space, but a vortex, that's a lot harder.
Kitsis:
I will say this: It's going down in the finale, and how it goes down, you will have to tune in and watch.

There's been a lot of speculation online that there will be a death in the finale. What can you tease?
Horowitz: I would say to the audience to take everything that you're reading in the press and about what's going to happen in the finale — and while we appreciate all the speculation — and set that aside. One of our themes this season has been magic has a price and that that price is going to be paid in the finale.

Sounds like a death is coming, no?

The season finale of Once Upon a Time airs Sunday at 8/7c on ABC.