Arthur didn't know why he was down here. There was no reason for him to be in the dungeons, except this pull. This pull to stand in the shadows and watch the gentle rise and fall of the sorcerer's chest as he slept.
It was late, and Arthur should probably be up in his chambers, sleeping, curled up in the warmth of his wife. Except he couldn't. Not when he was down here. Not when Arthur still had no idea what to do.
Arthur slid down the wall, face pale, eyes scrunched close, willing the tears to go away. He would not cry, he would not cry.
It was no use. The tears still came.
It was all too much. He did the only thing that made sense. He started to talk.
"I don't know what to do, Merlin. I don't know what I'm doing. I want to forgive you, but I don't if I can. There is so much which I have learnt, and so much which I still don't know. And it hurts. It hurts because I thought I knew you. Thought that we were friends, because we shared everything with each other. Or at least I shared everything with you. You were content to just let me be, to let me be in my own ignorance. I thought I knew you. I guess I was wrong."
The sorcerer in the cell shifted, and Arthur tensed, waiting, waiting for him to wake up. When he didn't, he relaxed again, body shaking with exhaustion.
"You were always there for me, even when no one else was. You stood by my side for years, through thick or thin, through every battle, every betrayal, and yet all along, you were betraying me. I've had a lot of time to think about this, Merlin. Too much time, if you ask anyone else. I understand why you didn't tell me to begin with," Arthur snorted, a sad smile crossing his face for a brief second. "I wouldn't have told me at the beginning. But after that? When we got to know each other, I would have chosen you, you know, if it had come between choosing you or my father, it would have been you. But I suppose I understand why you didn't tell me, even though we trusted each other, my father was still alive. I suppose that scared you. It would have scared me too. But after? After my father's death? You should have told me Merlin. You should have told me. I would have listened, if it had been you who had tried to save my father, and not your counterpart Dragoon, I would have believed you. Would have believed that you wouldn't intentionally kill my father. I believed that you cared about me, Merlin. And, as much as I might have complained about you, or made jokes about your incompetence, I did care about you, Merlin. I cared about what you thought, because you may have been one of the biggest idiots of all time, but you could be pretty wise when you wanted to be."
Arthur closed his eyes, turning his head away from where Merlin lay sleeping in the cell, shackled to the wall. He couldn't look at him, couldn't look at his friend.
"But, just like everyone else in my life, you betrayed me. If you had told me earlier, it may not have come to this, we could have figured something out, Merlin. But you didn't. You left me in the dark, did you even think about how I would feel when I found out? It's been years, Merlin, years since we met each other. I don't know how I'm going to go on. You weren't the first and you certainly aren't going to be the last person who betrays my trust. I thought you were special, thought you were the only one who would never, ever think of betraying that trust. But yours hurt the worst. When Morgana betrayed Camelot, betrayed me, I was hurt. But I was also hurt because my father had betrayed me as well. They were both at fault for that one, and I could pretend that it wasn't because of me, because I didn't have the necessary information to help. But then there was that debacle with Guinevere and Lancelot, and, and that hurt. Because I loved her, and she turned around and threw that love right back in my face. I thought that was going to be as painful as it got, but I was wrong. Because then… then my own uncle betrayed me, and well, would you fault me for thinking that there was something wrong with me? That maybe there was a reason for all of them betraying me. But then you always stood by my side, and I couldn't help but think, as long as you never betrayed me, it would all be good right?"
Arthur choked suddenly, tears now streaming down his face as he let out all of his emotions.
"But then I saw you. I saw you use magic, Merlin. I watched as you used it to stop those mercenaries, and, and I didn't know what to think. Why? Why? I asked myself, and I stood there, frozen in pain as I realised that my best friend, the person who I could always rely on, the person who I thought I shared everything with lied to me. Lied to me, just like everyone else I ever cared for has done. But this hurt more, because I thought I could trust you Merlin, thought that I could rely on you. And I was angry, and hurt, and… and then I saw your face. You were terrified of me. Terrified. Of me. And the worst thing? I understood why you would be terrified of me, why you would try and run. But you see, what hurt the most wasn't that you lied to me, it was when you did run. When you ran away because you were scared of me. And it hurt, because you said so many times that you trusted me, and yet, when it came to the truth, you didn't. I don't care that you have magic, Merlin. I care that you lied to me about it, for years."
Arthur scrubbed his eyes, but the tears wouldn't stop, still pouring down his face in a steady stream as he struggled his way through his confession.
"You know, all of the nobles are calling for your head?" he snorted. "I don't know what I'm doing, Merlin. I really don't. I know that I can't kill you, but I don't know if I'm ready to forgive you just yet, if I'm ready, if Camelot is ready for the return of magic."
Arthur stood, pushing himself up using the wall, turning to leave, running a hand down his face. He had almost left the dungeons when he gave in to the urge to turn to look back at Merlin.
"Things are going to be different from now on between both of us. I'm not sure I can trust you just yet, but you have to promise, Merlin, no more lies. Then, maybe then I can find it in my heart to forgive you."