Well, that didn't last long.

On Once Upon a Time's spring premiere, it looked like Emma (Jennifer Morrison) and Hook (Colin O'Donoghue) were getting along like fairy-tale franks and beans (What? It's a thing. Just ask Granny.). Unfortunately, in this exclusive sneak peek of Sunday's episode (8/7c, ABC), that little honeymoon period appears to have passed. Watch the video above to see what's gotten in the way of the lovebirds' happiness.

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We can't even imagine what sordid past he and Ursula (Merrin Dungey) have together. Did he eat calamari in front of her? Or maybe she once stole his hook? Fortunately, all is not lost between him and Emma. Even if her trust in him is tested, series co-creator Edward Kitsis assures TVGuide.com, "Hook feels that his job is protecting Emma's heart at all costs, so we will see that play out."

Emma will need all the support she can get. In the last episode, we also learned that the bat-creature Chernabog, who is drawn to the person whose heart has the potential for the most evil, targeted Emma, not Regina (Lana Parilla), as everyone had assumed. Now that the Queens of Darkness know this about The Savior, it remains to be seen what they'll do next. "It's not so much recruitment as exploiting that potential for darkness," says Kitsis. "We're going to see all of them try to see how they can use it for their own ends."

But the big question is: If Emma goes dark, will her fashion choices change? As we've seen on the show, evil tends to lean toward more flamboyant attire. Co-creator Adam Horowitz says, "You would have to pry that jacket from her." Kitsis adds, "If Emma were to turn to the dark side, if there's one thing you can say about our show, it's that our costume department always rises to the challenge."

Check out what else the series creators told reporters at a screening for Once Upon a Time:

If Emma were to embrace her dark side at all, how would Henry (Jared Gilmore) react?
Edward Kitsis:
Henry would do his best his best to keep her on the good side of the Force. Henry has the heart of the truest believer, and the truest believer always believes in you even when you're maybe going down a wrong path.

With Emma possibly going to the dark side, how could that change her powers up to this point?
Adam Horowitz:
It's less about what the powers are than how they're used.
Kitsis:
We've seen Rumple (Robert Carlyle) and Regina use their powers to help us, be it fighting villains or whatnot. And we've seen them rip out the hearts of 20 villagers because they wouldn't let Regina know where Snow White (Ginnifer Goodwin) was.

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We found out that Snow White and Charming (Josh Dallas) did something really bad that the Queens of Darkness know about. How bad can it really be?
Kitsis:
Hopefully bad enough but not bad enough that it's bleak, and [viewers] go, "Wow, what did they do to Once Upon a Time? That's the icky show now." What we really want to explore is if you've done a bad thing, can you come back from it? Can you become the person you want to be even if you didn't start out that way? And vice versa? What makes a hero and what makes a villain is a point of view.
Horowitz:
For the last number of seasons, we've seen a lot of our villains like Regina and Gold kind of go on a redemption arc where we've seen them start really bad and try to fight those urges and be their better selves to varying degrees of success. What we wanted to do was start to explore the idea with our heroes as well ... and how it will start to affect Emma as well.

There's a moment with Regina holding the dagger that looked like she was tempted a little bit by that power. Now that she's going undercover with the Queens of Darkness, will she be struggling as if she's a double agent?
Horowitz:
There's always an element with Regina of coming to terms with what she was and what she wants to be.
Kitsis:
Regina's going to have a huge curveball thrown her way.

In the spring premiere, Belle (Emilie de Ravin) said that "love is a weapon." Will someone try to use it that way?
Horowitz:
Always, in fact someone uses it in a way that is probably is my favorite usage of "love is a weapon" we've done on the show ever.

Are we supposed to infer that The Sorcerer is keeping The Author hostage?
Kitsis:
It feels that way
Horowitz:
It sure does. What's going on with The Sorcerer and The Author is something that hopefully will be clear pretty quickly.
Kitsis:
In the second half, that question will be answered as well as we will meet The Author.

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Are there other familiar faces you can tease coming up?
Kitsis:
Why yes, in fact, we are happy to tell you that Barbara Hershey will be reprising the role of Cora.
Horowitz:
It's more of Cora and Regina's past.
Kitsis:
Mommy issues always. In the first episode this year, we had Emma saying to Regina, "My job is to give everyone a happy ending, and that includes you." We saw her wanting to be friends with Regina, and that's really going to be explored in the second half.

What is the endgame for the season? The Author being able to change the path of people's lives seems like it could be really big.
Horowitz:
We started the season with Regina proclaiming she wanted to find The Author to have him write her a happy ending. We're going to make good on the promise of seeing what happens when you finally see he/she and try to do just that, and not just for Regina. Potentially it could have far-reaching effects.

Once Upon a Time airs Sundays at 8/7c on ABC.