First story about OUAT! It was hanging out in my head since quite a lot of time so I've decided to post it.

Tell me what you think.

Emma entered at Granny's to find Killian in front of Merlin, Nimue at his side. When he turned his face to her, she realized that he held Merlin's heart in his good hand. She opened her eyes, realizing what that implicated. Nothing of their kiss was real. Nothing of his declaration of love. He was playing with her all the time and, for what should be the first time during her life, she was happy to be Dark One because, hide under lots of darkness, the pain which would be unbearable, had become only a very unpleasant sting and a real need to act immediately. Immediately, a plan began forming in her mind. She got closer and whispered:

"You were playing with me the whole time,"

He smiled sardonically and answered:

"Once you lied about Excalibur, all bets were off and I know it was just a matter of time before you tried controlling me. And now, no one will ever control me again."

Emma looked at him, unemotional, when he turned to this damn sword and said:

"Go back from whence you came. Back to stone."

She came up to Nimue with anger and asked:

"I don't understand. Why are you helping him get his revenge?"

Nimue smiled slightly and answered:

"Don't be naive, Emma. Dark Ones never do anything without getting something in return."

Emma frowned and questioned:

"What do you want?"

"You're a Dark One. You know what we want. You want it, too," the first Dark One replicated with passion.

Emma knew immediately what it was and murmured, looking away:

"No. You can't"

Her interlocutor's smile grew wider.

"Yes, we can. And we will."

I must act now, before it's too late, said Emma to herself.

She turned around to face Hook and got closer, trying to reason with him one last time, putting her hands on his chest.

"Killian… your revenge is not your happy ending. I am. You told me that. If you destroy this heart, you will destroy you happy ending along with it."

She saw her eyes get softer for a split-second before Killian Jones lost his fight against the Darkness inside of him.

"No, Killian Jones told you that. Your lovesick puppy dog. But this man died the moment, you turned him into a Dark One."

Ending his sentence, he began to crush Merlin's heart who writhed in agony in front of Nimue's smile. But before he could finish his horrible business, Emma revealed a little bottle in a commonplace appearance and threw its content on him. The squid ink immediately worked and Hook stood still, dropping Merlin's heart who caught it.

"I'm sorry,' she whispered before knock him out with a wave of the hand.

She walked towards Merlin, helped him stand up and put him again his heart on his chest before apologize:

"I'm sorry. I… I couldn't just let him die. I thought our love could beat the darkness… but I was wrong," she sighed before take back her look determined. "But we are going to fix this, now."

With another move, she made appear Excalibur, the Dark One's dagger and the Promethean's flame in front of Merlin's surprised eyes. The last one asked:

"Did he not send Excalibur in its stone?"

Emma took the sword and gently caressed the name which was write in there, answering:

"He did but I intercepted the sword…"

"Emma, you know that to destroy the Darkness, you must put them into a…"

"vessel, I know," seeing his panicked look, she rapidly added: "I'm not going to use you, don't worry! I'm going to… pay for my mistakes and do what I should have done from the beginning."

Merlin looked at her and asked, horrified.

"You want me to kill you to destroy the darkness? No, no, no don't think about it, Emma."

Emma's face looked softer but her voice was still very hard when she answered:

"Listen, maybe, I still don't have use my Dark One's impulses but… but it's just a question of time. I hear it calling me and before I fall, we must destroy the Darkness and if you don't kill me… then, he would have to," She indicated Hook, still unconscious on the floor. "As Dark One, it could pass but not as Killian Jones. I can't ask him to do that…" she added, shaking her head.

Her eyes misted of tears, not at the idea of imminent death but for the people she will left behind. Her friends, her parents, her son… and Killian. Killian who had already lose all his loved ones, she didn't know if he could handle her loss. He will not be alone this time. He will have the others. She clung to this thought to not lose the little of courage she had found and turned towards Merlin, deeply breathing, she dived her hand on her own chest and put off her heart.

"Emma, what are doing?" the wizard exclaimed with a strangle voice.

She looked at her heart, of a red rose color, still bright without a trace of darkness. It's not logic. I embraced the darkness, it should be less shining and darker, shouldn't it?

As if he had read on her spirit, Merlin's answered:

"You embraced the darkness by love and love is an extremely powerful magic. It compensated for the blackness that brings the Darkness to you heart. Now, tell me, what are you doing?"

Emma, finally, took her eyes off the heart and looked at Merlin, asking:

"You are going to pierced me with Excalibur, aren't you?"

He nodded with hesitation and let her continue:

"But then, my family will have to go back to Storybrooke and Zelena will not help then this time so… when you will have killed me, give Killian my heart. If he crushes it, he will cast the Dark Curse."

Merlin nodded again then watched Emma got closer of the two blades and the flame. In an instant, she turned it in and begin to bring the blades together. The Dark One, finally, caught Excalibur whole and gave it to Merlin. He took it and Emma keel down and slowly kiss Killian before waking him. A second after, the last one began to groaned unintelligible things and Emma got up to whispered to Merlin:

"Your move, now. Go ahead, trap the Darkness, I'm ready."

She closed her eyes and waited. At the beginning, she felt nothing when, suddenly, it was as if we put her a great burden off that she never realizes the existence, she sighed of happiness and opened her eyes. She immediately regretted her choice. Her look fall instantly on Killian who had get up, still half groggy. Nevertheless, he was enough conscious to realize what she was going to do. His eyes shone of despair when he cried:

"Emma! What are you doing?"

And his voice… his voice which was hot and full of love again even marked with hopelessness… his voice which hadn't the mockery of the last time. It the voice of Killian Jones. Of her Killian. The Killian, she loved. She looked at him dearly before saying:

"I'm doing what I should have done from the beginning."

His slightest time as the Dark One had teach him one thing: to destroy the darkness she must die. She saw his look fall on Excalibur before he exclaimed:

"No! No, Emma, don't do this! Please!"

The despair was now a distant memory compared of what was shining in Killian's eyes. Emma's heart would have fell apart if she had it and she hated herself to make him suffer like that but she couldn't flex.

"I'm sorry, Killian but I must do it. It's the only way to put off the darkness in both of us. For you, to be free of it!"

She watched Killian's eyes misted of tears and his body felt on the floor… he had understood that he was powerless.

Taking a deep breath, she nodded to Merlin who got closer and whispered:"

"You know that he's never going to forgive himself for your death?"

She began to cry but answered:

"I know but it's… it's a good thing if he blames himself because that means that he's got back to being the man I love."

Merlin didn't say anything and handed the sword in front of him. Emma closed her eyes, trying not listening Killian's supplication cries and prepared herself to die.

Nothing could prepare her for the blast of pain that she felt when Excalibur penetrated her. She fought as she could against the fierce dragon who teared her guts apart but it was a fight she could not win. She let a cry escape and felt herself fall. But the choc never come, she had been caught by powerful arms. Emma didn't open her eyes but smelt a scent of rum and sea.

Killian.

She felt herself derive between definitive death and painful life when a blinding light burned her retina. Resigning herself to open her eyes, she saw that she was Emma again. Not the Dark One. Her eyelids became heavy but she succeeded to meet Killian's look. What she saw? Pure agony was shining in his eyes' iris and his face was soak of tears which didn't stop to come.

"Hold on, Emma! I beg you! I'm sorry, please don't die! Don't leave me!"

She raised a hand to caress his cheek, wiping a little bit his tears before using her last sparkles of energy to whisper:

"I… I love… you,"

Then, she let the warm grip of the death take her soul and gave her last breath in the arms of the person she loved the most in this world as another. She didn't hear Killian's pain scream. Or, her family came running. Or, in a last moment of lucidity, Killian crushed her heart.

Emma Swan didn't feel anymore.

So? Did you like it! I hope there is not too much mistakes, English is not my maternal language. Tell me, in the reviews, if you want a next chapter or the same one but in Killian's POV! Thanks for reading!