I wrote this a long time ago but never got around to posting it. Hopefully some OUAT fans are still around to enjoy it!

"I can't tell you what went on between us until I fix it." Emma says and it's the most emotion Killian's heard in her voice in weeks.

"Why?" He asks. He can't understand the quiver in her voice, nor the guilt in her eyes. Doesn't she know that he loves her more than any bad deed she could've ever done? That he'd do anything to save her from this? "Don't you trust me?"

He means it as encouragement, but she flinches as if struck. "Of course I do!" Her voice shakes and she clutches his jacket like he might disappear. "I always have, even when my walls were up and I was too scared to show it."

"Okay, love." Killian says carefully, taken aback by the raw desperation behind her words "It's okay."

"I'm not doing this because I don't trust you. I'm not trying to take your choice away, I just need to make things right first."

Silently Killian notes the confirmation that she is atoning for something. If only he can get to the bottom of it, maybe he can bring her back into the light. "But you're isolating yourself and hurting people. That's not how you make something right. There has to be a part of you that still knows that."

"There's no other way."

"There always is, you taught me that." He sighs. "You find one by talking to your family. Talk to me, please."

"Killian." It's both a warning and a plea.

"You say you trust me," He whispers because they're so close now he can feel her breath. Her grip on his jacket tightens and Killian realizes he's struck a nerve. It might be bad form to exploit it, but if he can finally learn what happened and ease that guilt weighing her shoulders, there's very little he's not willing to do. "if that's really true, then trust me now. Trust me with the truth."

"I-" Her eyes wonder the room, conflicted… considering.

So Killian brings his hand to her cheek, allowing himself a small smile when she sinks into it, and he tries one more time. "The only thing that matters is what we do here, today. Camelot is just a memory."

Emma finally, finally meets his eyes and Killian feels both relief and dread, because he knows that he has her now. She leans in to kiss him and it's soft and desperate, and Killian has the terrible thought that she's saying goodbye. He steels himself, regardless of what she's about to tell him he won't break his word - he will forgive her, and he will help her. He can't imagine anything that could make him even consider anything different, but he vows not to turn his back on her even if it does.

"Emma," Killian breathes when he sees the tears rolling down her cheeks. She shakes her head and hugs him tightly, resting her cheek against his shoulder.

She whispers it. A single sentence, just seven words, and he can't comprehend it but his body is a little quicker and it tenses in her grip. "What?" He asks with genuine confusion. He's too slow to realize he doesn't really want to hear her say it again.

"I turned you into a Dark One."

There's pause, a moment where Killian doesn't know what to say or do, so he doesn't move from her death grip and they both stand there in silence. First there's denial - there has to be another explanation, she's lying or confused. If he was… that, he would know. Right? But then there's the fact he hasn't slept since returning from Camelot (he's been worried about Emma, perfectly normal), the flashes of anger (he's always had a temper)… strange overall feeling of being wrong? There was also that one time a light bulb exploded when he cut himself shaving and okay he can't really explain that one. Next comes the anger, his old friend. But it's only there for a moment before Killian squashes it to the back of his mind, and he knows it won't stay there long but he's not going to go there now.

"Oh." He says out loud.

"Oh? That's all you have to say?" She pulls back far enough to look at him and Killian is careful to scold his features into something unreadable.

"Why?"

He can see her trying to read him and the almost physical frustration when she can't. A bitter part of him is glad – she can know what that feels like now.

"You were dying and it was the only way to save you." Her voice shakes and Hook's glee quickly fades. "I couldn't lose you, Killian. I'm sorry."

"I… couldn't have wanted that." He says carefully, still trying to fit the pieces of this story.

"You didn't." Emma admits and now her voice is hesitant, and Killian realizes that once again he's struck a nerve. "You asked me not to, but I couldn't just let you die! I know it was selfish, I do."

That's when it finally begins to make sense - taking their memories, trying so hard to convince them she's the villain. Only she wasn't the villain. "What did I do?" And there it is, his worst fears come true. Falling back into darkness, hurting the people he's grown to love like family. "I didn't forgive you, did I?" He asks when Emma doesn't answer. "And Merlin, he said the Dark One had found him, but he was talking about me… because I killed him?"

"That was the darkness-" She tries touching his cheek and Killian does react then – flinching from her touch and it's only her grip on his jacket that stops him from stepping out of her embrace altogether.

"Don't make excuses." He warns. There's something dark and angry in his tone and he fights to reel it back in and slip his mask back on.

"Okay." Emma says carefully. "You said Camelot was just a memory, that we could make different choices today."

He wants to tell her he can do that, but he also wants to go back to his ship and maybe break something, and definitely pay Crocodile a visit while he's at it. Neutral is the best he can do at the moment. "But how can Camelot be a memory when I don't actually remember it?"

Emma's eyes widen. More resistance, more secrets.

"Surely there's nothing worse than what you've already told me?" He tries to inject some humor, but the question comes out more desperate than anything else. He's not sure he could handle another such surprise.

"No, it's just… we had some disagreements."

"I gathered that."

"And I made mistakes-"

"Clearly." That's the anger winning out.

Emma fails to hide her wince. "You thought you couldn't trust me… because you thought I didn't trust you, but I did, I do!"

"Right…" She's mentioned trusting him so many times now and Killian finally realizes she's trying to prove it. Although without context he's confused how their disagreement about cursing him with the darkness turned into an issue of trust.

"Can't we start over? I already told you everything, if we just get rid of the darkness first-"

"So it is about trust then." Killian realizes suddenly.

"What?"

"You think remembering will make me give into the darkness. Which is the same reason you took all of our memories, and didn't want to tell me the truth... You really don't trust me, do you?"

"I do trust you, but I'm terrified of losing you." She tightens her grip before he can slip away and the surge of anger is once again gone because she's crying, raw and honest crying and he hates that he's the reason why. "Don't you see how far I went to not lose you? I know I did everything wrong, but each time I tried to keep you it just pushed you further away and I didn't know what to do so I kept trying."

"Emma…" He uses his thumb to wipe her tears away. "Whatever happened between us… I need to hear it from you. Don't make me hear it from someone else." He asks.

"Okay." She nods after a moment. "Wait here."

As Emma leaves to retrieve his memories, Killian sighs and sits down on the couch, resting his face in his hands. A part of him still doesn't really believe it. Him, a Dark One? He fights the urge to test himself for magic, if it's there he doesn't really want to know. Not yet, at least.

Suddenly the front door slams open and the cavalry storms in. Regina is at the front, palms spread out, ready for a magical fight, and Emma's parents are right behind. They falter when they see him there.

"Hook?" David asks.

"What are you doing here?" Killian asks them.

"Your girlfriend sped up Zelena's pregnancy and I want to know why. I'm not standing around waiting for her to kidnap Robin's daughter." Regina says. "Where is she?"

"Why would Emma want Zelena's baby?" Killian frowns. Everything else Emma's done has fallen into place, but speeding up a pregnancy? Kidnapping babies? No, there must be another explanation.

"I'm not waiting to find out." Regina snaps, then hesitates, staring at him. "Are you okay?"

And yeah, he must really look pathetic if even Regina is concerned. "I'm fine." He stands, trying to shake whatever vulnerability she's glimpsed.

"Did Emma bring you here?" David asks.

"Kind of… I sought her out. I was trying to get to the bottom of this."

"And did you?"

Hook hesitates. He should tell them the truth, but the moment he does - the moment he tells them he's a Dark One, that's all they're going to see. Even Emma doesn't really believe he can fight the darkness, so why would her family?

David steps forward. "Hook, if there's something you know-"

"My plans are for me alone." Emma appears in the doorway. Her voice is cold and hollow, a perfect mask of the villain Killian now knows she is not. But now no one's looking at him anymore and Killian realizes that was her plan all along. She waives her hand and her family poofs away.

"They should know the truth." Killian says.

"You didn't tell them either." Emma counters. She pulls a dream catcher from behind her back and hands it to him. "The full story of what happened in Camelot is there."

He takes it carefully.

"I can…" She waves her hand for emphasis.

"No. I can do it… I think." He lowers the dream catcher, thinking. "But not now. I think I've had enough revelations for today."

Emma tries to hide her relief. She reaches out and Killian shies away from the contact. "Don't." He asks her.

"You still hate me." She doesn't even voice it as a question.

"What? No. Gods Emma, I need to think. To sort through my own head."

"And then?" There's the smallest hint of hope in her voice, something Killian has missed dearly.

He wishes he could latch on to it the way he has in the past. "I'm still here, aren't I?" He says instead, it's the most reassurance he can give her right now. "But you still haven't told me everything, have you?"

"What?" She seems startled.

"Zelena's baby?"

"I'm not after Zelena's baby."

Killian sighs with relief. "Then what are you doing?"

"I did speed up Zelena's pregnancy, to protect the baby."

"Protect it? From what?"

"Killian, Merlin can't help us get rid of the darkness anymore. There's only one way now, it must be contained in a single vessel and struck down by Excalibur's enchanted blade."

Killian tenses, finally understanding. "You're going to kill Zelena?"

"She's killed countless people and will do the same to any one of us given the chance. Don't tell me she doesn't deserve it."

"You're talking about cold-blooded murder!" Killian snaps.

"Then tell me a better way?" Her voice shakes and Killian can't find it in himself to pull away again when she latches onto his arms. "Tell me a better way and I swear I'll do it."

"I-" She's right. For the darkness to be destroyed someone has to die. She's also right that Zelena has it coming, but if he lets Emma do this now, she will forever have that blood on her hands. And Killian swore to save her. "Maybe there is one..."

Emma freezes. "What?"

He can't forgive her, at least not while fighting the darkness. And he is bloody angry, at Emma, the Crocodile, himself. But here she is, finally open and trusting and Killian has to at least try to fight it for her. And he absolutely has to save her. But maybe for once his old blood lust is the answer.

"You said you have to give the darkness to someone," The plan quickly forms in his mind. "so why not give it to someone who actually wants it?"

"Who would ever want this?"

"Why it's simple. The one person who actually knows how to control it."

Emma's eyes widen with the realization. "You want to give it back to Gold? The same man you spent centuries trying to kill?"

"I admit the thought of finally getting my revenge did cross my mind." He says darkly. "But that wouldn't solve our problem, would it?"

"So what, you're prioritizing?"

"Exactly. Unfortunately, revenge falls pretty low on the list at the moment." He smiles. "It's a good plan."

She seems to finally consider it. "Maybe… but Gold's different now. I made him into a hero, he won't want the darkness back."

Killian shakes his head. "Yes, he will. Don't forget I know him better than anybody. That's how I knew the dagger he gave Belle was fake, and that's how I know this now – no matter what he says or does, he will do anything to get that power back."

"And the darkness will have a vessel that can actually control it." It's like a weight is lifted off her shoulders. She smiles at him, overtaken by excitement and hope. "Killian this can work. We can actually get rid of the darkness without hurting anyone."

"Aye." Killian returns her smile. Emma isn't going to hurt anyone, but she was right that Killian isn't about to hand magic back to his old nemesis either. He wasn't lying about prioritizing – saving Emma comes before anything else. But he's about to take a page from the Crocodile's book – he's going to have it all. Once the darkness is back in the Crocodile Killian will use Excalibur to kill him and end both the darkness, and his revenge once and for all.

I've got another one shot inspired by the Dark One Hook episodes, might post that one too if people are interested.