Spoiler warning: The following contains plot details for the Season 5 premiere of “Once Upon a Time,” titled “The Dark Swan.”

Storybrooke is going to look a little different in season five of “Once Upon a Time,” since the show’s supposed Savior, Emma Swan, has officially turned to the dark side and embraced her mantle as the Dark One. Despite her friends and family’s best efforts to help Emma fight her evil impulses, the final moments of the season premiere brought our heroes back from Camelot with six weeks of missing memories and one seriously antagonistic Dark Swan hellbent on revenge.

Variety was among a number of outlets to talk to “OUAT” bosses Adam Horowitz and Eddy Kitsis about the events of the premiere and what’s ahead for our heroes and villains in season five — read on to find out what we learned.

Time on our hands: The show will once again utilize flashbacks to help tell the story of the past six weeks. Kitsis compares the beginning of season five to the back half of season three, which jumped between the present day and the characters’ forgotten year in the Enchanted Forest under the rule of the Wicked Witch. “We are going to be flashing back to Camelot and then present-day Storybrooke, with a few origin stories,” including backstories for Merlin, Arthur, Guinevere, Lancelot and Merida, according to Kitsis.

However, Horowitz promises that “it’s not gonna be the whole winter before we catch up [with what happened during those six weeks], and it’s not necessarily everybody at the same time.” Despite the influx of new characters in Camelot, Horowitz also insists that the story will focus on “our core group of characters and what they’re going through in Camelot with regards to Emma… We’ll see what seems to have happened to her and [explore] that mystery and how they can or can’t help her.”

Bad to the bone? Whether Emma manages to rid herself of the darkness or lets it take her over completely, Horowitz says, “it’s going to affect her, and the ramifications of what happened in this premiere are felt throughout the entire season. While a lot of the story in the first half we tend to wrap up in the midseason, there’s bigger issues that are introduced as early as this episode that will carry over for the whole season. We’re trying to tell two separate parts of episodes and connect them. Emma’s journey is going to encompass the whole season.”

Kitsis points out that we saw Emma trying to resist the darkness in the premiere, but by the time six weeks have passed, she’s obviously had a change of heart. “So we’re wondering, what happened? And how did that happen? That’s what we’re going to explore… what makes you succumb to the darkness? What makes you resist it? Her relationships with everybody are going to be tested. We love the idea of watching Hook fight for her, as well as Regina and her family. ‘Cause Emma came to Storybrooke a non-believer and now she is a leader and she’s united everyone. So as you saw there, when you take the leader out, everyone starts bickering.”

Emma’s dark turn will also present opportunities for character growth among her former allies — most notably Regina and Hook. “We love the notion that two of the people that she has unexpectedly grown closest to over the years, Regina and Hook, are both people who’ve battled darkness themselves,” Horowitz points out. “The fact that she is facing darkness and they’ve faced it and how their experiences can inform what she’s going through and either help or hinder her is something that we want to explore this half of the season and beyond.”

Even though Emma has switched sides, fans can still expect plenty of interaction between the new Dark One and her loved ones.

“Going forward after the premiere, on the Storybrooke side, our characters are really wrestling with the mystery of what could they have possibly done to Emma to make her this way? And Emma plays her cards very close to the vest. But that does not prevent her from interacting in very direct and close ways with characters like Hook, Regina, and Henry,” Horowitz teases. “So while there is this mystery that’s going on of what may or may not have happened, we’re going to see relationships move forward in a new way, in the present, which is where we have a very dark Emma appearing. And at the same time, in the past, we’re going to be seeing these relationships also interacting, and a lot of choices are going to be made by different characters, by Emma and the people who care for her, and some choices that may seem like the absolutely correct thing to do, are going to turn out to be maybe the worst thing to do.”

Hooking up: While some fans may be frustrated that Emma and Hook’s relationship hit another snag right when it seemed to finally be on solid ground, the producers promise there’s a reason for every narrative choice they make — and it’s not because they want to rile up the fans.

“With those characters, for example, we don’t refer to them as ‘Captain Swan.’ It’s never talked about that way in the writers’ room. The way we do it, is we talk about Hook, and Emma, and Regina, and Henry, and we talk about the characters and what’s going to happen with them. The relationships that form and that have obstacles — or [don’t] have obstacles — are part of their journeys. There’s no agendas of, ‘What are we going to do with this relationship or this ‘ship?’ It’s more about the story we’re telling in the season,” Horowitz insists. “And you can see from the premiere, yeah, at the end of last season, they’re ripped apart, but [in the premiere] they’re back together dealing with the issues.”

Kitsis agrees, “He’s very much fighting for her, and I’d say that, like a book, you can’t open ‘Hunger Games’ and then on chapter three go, ‘Why didn’t they tell me who won? This book sucks!’ As we do the split seasons, the whys of all of these [choices] will be revealed by the end… Their relationship is a big part of the first half of the season. It’s going to take the 11 episodes to get there.”

Regina reigns: With the Savior gone AWOL, season five will see Regina step up to the plate and try to assume the leadership role that Emma vacated, with mixed results.

“Regina’s a character who has grown a lot over the years and has tried to put her evil behind her and do good, but that part of her, the evil and the darkness, is a part of her,” Horowitz says. “So she is kind of struggling with how does she do the right thing and how does she help Emma?”

“You’re going to see in Storybrooke… as good as Sneezy was as Sheriff, he went down pretty quick. So it’s going to be everyone looking at the mayor,” Kitsis notes. “It’s one thing to ask everyone’s forgiveness; it’s another thing to lead people. So we’ve seen Regina on our side helping out the heroes, but she’s going to be thrust into a leadership position in saving the town, a town where quite honestly, a lot of people are still frightened of her.”

“That also impacts Regina’s relationship with Snow, who’s someone who has been a leader and people have turned to,” Horowitz says. “It becomes, hopefully, very complicated and messy in a good way, which is these kind of familial and adversarial connections are now forced to interact in new ways.”

Snow problem: According to the producers, Emma’s descent into darkness will put a new strain on Snow White and Prince Charming’s relationship, especially since the two will forge new friendships in Camelot.

“We are going to see Arthur and David bro out; they’re going to have a bromance unlike any other,” Kitsis says. “We feel like David the character, now that his daughter has magic and Regina is there, he’s starting to be like ‘I was the guy who used to slay dragons – what’s going on?’ So we’re gonna see a reawakened hero.”

Meanwhile, Kitsis notes, “Mary Margaret and David have a past with someone from Camelot… David is going to become pretty close with Arthur, and so we know that Mary Margaret, if we remember back to season two, was able to have a child because of Lancelot. So we’re gonna see those two – as desperate parents wanting to save their daughter – feeling powerless and not knowing who to trust, so there’s gonna be a bit of palace intrigue. When you’re married and there’s a really bad situation and you can’t do anything about it, sometimes you turn on each other. We’re gonna see Snow and Charming fight in a way we’ve never seen before and we hope that the fact that they share a heart wins out, but it’s all because of the emotion of just trying to save their daughter – we’re trying to play that in as real a way as possible.”

That could imply a little more darkness from Snow, Kitsis hints. “We saw Snow White kill Cora, and we saw her rip a baby from Maleficent, so she’s kind of scarred a little bit… When you try to save someone that you love, and you feel helpless in doing it, then that’s kind of what we’re going to explore. Emma’s off on this thing, and it could be a metaphor for addiction, it could be a metaphor for darkness. She’s behaving in a way and you’re going to see a lot of the people around her who love her feel powerless in how to help her, and so it’s that intensity that we really want to dive into.”

Secrets of the sword: As we discovered in the premiere, the mythical sword Excalibur was broken when Arthur pulled it from the stone, with half of it forming the Dark One’s dagger. We got our first glimpse of Merlin as the mysterious usher who issued Emma a dire warning when she snuck into a movie theater as a child, and that warning will echo throughout the season.

“He warned Emma not to pull the sword, we saw Arthur pull the sword, and we realized that the Dark One dagger and Excalibur were meant to be whole, so we’re going to explain to you why that is, why Merlin is where Merlin is,” Kitsis says. “Merlin is going to get an origin story that is going to explain his whole thing, and the Emma of it is going to come in, so that arc will be explained and that warning will be explained right in the first seven episodes.”

Camelot will also provide plenty of opportunities for “adventure and romance,” the producers promise, including Henry’s first crush in episode two. “Beyond just whatever mythology in our show that we’re exploring, being in this place of romance and adventure has an effect on each and every one of them, and we’re going to see stories where that really impacts them. While the stakes are super high for Emma, there’s still room for the fun and swashbuckling adventure,” Horowitz says.

ONCE UPON A TIME - "The Dark Swan" - Immediately after becoming the Dark One, Emma disappears and the heroes must band together to save her, but first they have to find her, which will require the help of an unlikely ally. Meanwhile, in the Enchanted Forest, Emma struggles to resist her dark urges as she searches for Merlin in the hope that he can stop her transformation. Along the way to Camelot, she gets help from the plucky and brave warrior princess Merida, as well as King Arthur and his Knights of the Round Table, in the adventure-filled season five premiere of "Once Upon a Time," SUNDAY, SEPTEMBER 27 (8:00-9:00 p.m., ET) on the ABC Television Network. (ABC/Jack Rowand) AMY MANSON

Feeling Brave? We haven’t seen the last of Merida, whose origin episode will take us back to Dunbroch and give us a glimpse of her family thanks to flashbacks. “Merida’s problem [is] she punches first and asks questions second,” Kitsis notes. “We’re going to find her in the middle of a very intense situation. We’re definitely going to explore her story more.”

She’s not the only familiar face we’ll see this season — the Dwarfs and Granny will also play a much bigger role, having been sidelined for many of the show’s previous adventures. “It was a conscious choice to bring them along for the ride to Camelot so that we could see some of the people we’ve loved over all the years of the show and give them moments and fun and make them a part of it all,” Horowitz says.

“Being the fifth season, we’re going to hopefully see as many old faces as we can this year,” Kitsis promises. “For us, we just loved the idea of how annoying it would be to be a Dwarf and you were the guard in the pilot, and now there’s all these adventures and everyone’s like, “What was Neverland like? Oh, you didn’t go? I thought you were Snow White’s guard?” That’s what it really came down to in the writers’ room. We just loved the idea of Grumpy being upset about it and feeling jealous.”

Some of those old faces include Mulan and Red Riding Hood, who both disappeared due to their portrayers landing regular roles on other shows. “We’re not just planning to drop them back in the show with no explanation and just say, ‘Oh, they were over in the corner.’ We do want to give a taste of where Mulan has been and what she’s been up to and what she’s been going through. The same with Red,” says Horowitz. “And there are other characters who may return, as well, and we want to do that as well [with them]. We want to honor the idea that their lives, all these characters’ lives have been going on during now the fifth year of the show, and we wanted to give a taste of where they’ve been and now see how they can reconnect with everybody else.”

As for Mulan’s implied attraction towards Aurora, which was introduced in season three but never fully explored, the producers promise that they have a plan. “We know that [the LGBT] community have been big supporters of the show, and we would love to be able to tell a love story that reflects that,” says Kitsis.

“We want the show to reflect that world as it is now and whether that’s going to be with any particular character, we’re not going to say,” Horowitz agrees. “It’s something we want to do this year, and it’s something that is due and important to do on the show. This is the world we live in.”

All that glitters: While Mr. Gold remained comatose and on the verge of death in the premiere, Rumplestiltskin got plenty of airtime as the manifestation of all the previous Dark Ones in Emma’s subconscious — serving as the devil on her shoulder despite her efforts to reject the darkness.

“There’s different forms of Rumple. We saw this kind of apparition in her head form and then of course there’s Mr. Gold in Storybrooke and we’re going to explore what’s going on with him… We’ll explore this season the mythology of The Dark Ones and who they are and who they were.”

As for the real Mr. Gold, Kitsis promises, “His arc in Storybrooke is something we haven’t fully seen before. It’s going to go right into his very essence as a character.”

And now that Belle has received a very familiar rose that should please “Beauty and the Beast” fans, designed to warn her if Gold is near death, we’ll also see her in the thick of the action.

“My favorite Belle is the one where she’s strong. And we’re going to see that strength this year,” Kitsis promises, while Horowitz notes, “Belle cares about what’s happening to Gold/Rumple right now, but that doesn’t mean that all is forgiven and everything that happened before doesn’t need to be dealt with. It does.”

Kitsis agrees, “When something really horrible happens to someone, you tend to push pause and make sure they’re okay and then you can go back to being mad at them.”

“Once Upon a Time” airs Sundays at 8 p.m. on ABC.

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