Merlin's heart let up through his throat as he saw Morgana crouching next to Arthur. He pulls the sword out as quietly as possible.
"I blame myself for what you've become Morgana, but this has to end.", he says softly. Morgana turns and faces him and he expects some snappy remark or insult or brag about her powers but instead she cocks her head to the side and replies simply with:
"Why must this end? Because you have wreaked so much destruction and pain on this land Morgana, that's why.",Merlin retorts.
"No, why protect him with your life, why protect him like this?" she asks gently.
"Because he's my friend."
"So was I. Didn't stop you trying to kill me. " Her words, lightly as they has been delivered, were much more than just a flippant remark to Merlin. Because this was the truth he's run from for so long. That he had played his hand in Morgana's descent into the maniacal evil that now gripped her. Arthur looks confused because he doesn't know and how could Merlin have ever told him that he'd poisoned his sister before she'd turned against them? That he could have been the reason she turned against them?
"You, you would have killed us all, Morgana, that day.", Merlin says saddened.
"How? I had no part in whatever was going on - you were the one who looked me in the eyes and watched as I died because I trusted you." And it's in her eyes, he can see there's truth. And there's hurt and betrayal and agony. The saying eyes were windows to the soul - Morgana's must have been floodgates that she had latched shut for so long but now, in this moment, she was laying herself bare. She genuinely believes she had nothing to do with what had happened that day.
"You, you were the source Morgana - the sleeping curse, you were the source. The only way to stop it was to kill the source. I made a choice that I am always going to regret Morgana. Always. But I did without joy, but for the sake of a kingdom." Morgana's brow creases in confusion. And then, it's like a light switched on in her mind.
" Morgause. ", Morgana gasps out. And it's like a stone plummets down his stomach. She had been unaware?
" I thought, I thought you knew. I though you had planned this"
"No! No I hadn't. I trusted you. I thought you were my friend!", and the pain bleeds through.
"I'm so sorry, Morgana but I thought it was the only way to save us all." There's a silence which falls thick and fast.
"I would have done it willingly you know.", Morgana says finally.
"Done what?", Merlin asks confused.
""The poison, I'd have drank it willingly. For all of you, for you, because I trusted you. For Arthur, because I love him like a brother. For Gwen, because I love, I love her. Don't you see this is what you did to me?"
" I'm sorry. I'm so sorry. If I could change it, I would Morgana, I would. " Morgana watches him sadly.
" I forgive you Merlin. Please forgive me. " Morgana pulls the blade from his hands before Merlin can react. Arthur strains himself towards her, scared for Merlin and Merlin jumps towards her. Morgana pushes the blade towards herself and then through herself. She gasps in agony. Merlin moves forward and catches her. He pulls the blade out slowly and lowers her to the ground.