Once Upon a Time bosses, cast on Dark One twist 

'Once Upon a Time': The battle for Emma's soul comes to a head

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Warning: This story contains major spoilers from Sunday’s episode of

, viewers finally discovered why Emma (Jennifer Morrison) went dark in the first place — seriously, this is your last chance to look away before you get a major spoiler. Everything Emma has done since the season premiere has all been in service to Hook (Colin O’Donoghue).

Under threat of her family being killed, Emma was forced to turn over the Dark One dagger and the Promethean flame to make Excalibur whole for Arthur (Liam Garrgian). Ultimately, Hook came to their rescue, but he was cut by Excalibur in the process, which has unforeseen consequences.

When Emma went to piece the sword and dagger back together to cast out the Darkness once and for all, she learned the hard way that a cut from Excalibur can never be healed as Killian began to bleed out. To keep Hook from dying, Emma tethered him to Excalibur, creating a second Dark One. That’s right, Hook has been a Dark One all this time and no one — not even him — realized it.

“I thought it was a cool idea,” Morrison tells EW. “There’s something really romantic about it. She doesn’t want him to die. She doesn’t want to lose this man. She’s lost all the people that she’s loved in different ways. She wants to put her foot down and say, ‘No, this is the guy, I don’t want to lose this one. Even if we have to make some crazy choices to fight to overcome the Darkness, I’m going to do whatever it takes.’ It’s a really romantic gesture.”

agree with her choices. In his dying moments, Hook begged Emma to not only reunite the sword and dagger to save herself, but he also pleaded with his love to let him die, knowing he couldn’t handle the Darkness as she had. And with Zelena (Rebecca Mader) pointing out that there’s more to be revealed as to what happened in Camelot, Hook may soon discover there is someone else to blame for their current predicament — as teased in this week’s Spoiler Room.

The rest of the group will feel much the same about Emma’s quick decision, causing a whole new host of problems in Storybrooke. “They are not going to be pleased,” executive producer Edward Kitsis says. “The person who is going to be least pleased is Hook, because the thing he hates most in the world is the Dark One. Rumplestiltskin [Robert Carlyle] took away everything from him and now Emma turned him into the one thing that he hates. Worse than that for him, we’ve seen Emma really, really struggle with resisting the Darkness. Hook knows after centuries of being a pirate, he does not have her willpower. You can’t sneak an alcoholic alcohol and expect him not to drink. All of that is going to play out and it’s really going to test their relationship and their love.”

“It’s so complicated,” says Josh Dallas. “Emma did it in order to save him, which is kind of an honorable, hero thing to do. Whether it’s misguided for the outcome of what it was, he thinks it’s an honorable thing. Is he happy that she did it? No, he’s not happy about it, but he can understand it at least. I don’t think Charming is looking at the world now so black and white. Things are more gray now.”

Ginnifer Goodwin adds: “I think Snow always trusted her motivations. But also what’s so brilliant about the writing is that most of the Dark Ones acted with good intention. They were all trying to fix a problem for the better, it’s just that other factors get in the way.”

Having played a role in Emma’s fall from grace, Regina (Lana Parrilla) is a little bit more understanding. “Regina has a very negative reaction to the whole thing, because she thinks it’s the stupidest idea on the planet, and yet she can’t really judge  her because she had a hand in Emma taking those steps toward becoming the Dark One,” Parrilla says. “She asked Emma to save Robin. She understands wanting to save the person you love, but it’s just complicated things even more. We had a problem already and now we have a bigger problem, because now we have two Dark Ones!”

Though they’re not happy about Emma’s choices now, the Charming family and friends are certainly on the road to recovery upon the discovery that everything Emma has been doing this season was actually for good — something Morrison was clued in on from the beginning. “Yes, I did know that,” she says. “I didn’t know every single detail. It seems to be the case where we get big, sweeping understandings of things, and then the details episode by episode in terms of how it all ties together intricately. I did know that everything she was doing was to save Hook from the beginning.”

Even Henry (Jared Gilmore) may be more understanding that his mother forced his first crush to turn him down. “Henry has learned that although your parents can be dark and your family can be dark, there’s still that loving and caring thing because Emma helped Henry along the way,” Gilmore says. “Although it was really to further her own goals, there was still that loving and caring spark that all moms have.”

Now the problem is what Hook actually wants after succumbing to the Darkness. “There are a few things as the Dark One that are more complex,” says O’Donoghue — and if you’re wondering why there isn’t more with him in this story, it’s because EW will soon post a full interview with him on his transformation into the Dark One, so stay tuned! “They all have slightly different things that they want out of the Darkness. A big part of who Hook is, and who he has been for hundreds of years, is that motivation for revenge, and you definitely see elements of that come up.”

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