So, yeah, I was listening to Olly Murs' Dear Darlin' (love it/him btw), and it sort of popped into my head.

Thor jolted awake, yet another nightmare, the same old twisted images of his brother, full of hatred, fighting, and then falling. Frigga had said that writing down his feelings may help, but it hurt him to think that Loki would never read his letters, never know how he felt. Walking over to his desk, he brought out some long forgotten pieces of paper and began writing, his hands shaking...

Dear Loki,

My brother. Always my brother. It has been a week since I saw you fall, but only a few short hours since I last saw your face, for I see it in my nightmares every night. In your eyes I see your suffering, the pain, the anger...the desperation. Mother says you wanted love, and adoration, not through power and the throne, but from me, and Father. She says you would never admit it, never tell her that all you wanted was for father to be proud, and look at you the same way he did me, but she knew, she always knew. I was proud of you Loki, you were most precious to me, the one who had stayed by my side through everything. We grew up together Loki, the day father brought you to my room was the day I felt complete; I was only a young boy, not even old enough to read, but when I saw you, when they let me hold you, the empty puzzle piece fit into place. And it is missing once again, and nothing, no amount of ale, or war, blood or food can fill it, I'm not even sure the Lady Jane could replace it. I watched you grow, watched as you found your powers and molded them into place like the vines of Mother's most beautiful roses. There were nights you woke me, tear filled eyes that you refused to allow to fall, not wanting me to see you as weak. The nightmares that woke you not allowing you the comfort of sleep unless it was by my side, calming you and fighting off the monsters. I saw your frail body fighting off infections and illnesses that seemed to follow you like a shadow, especially in the hot summer days when you would have fevers even an ice cold bath could not fight off. You were always so strong, and confident, whether you felt so inside or not. There were times you followed me on adventures that you knew would end badly, but you were never selfish, you chose to come to protect me, when it should have been me protecting you. You once carried me home, dragging my almost dead weight in your arms when I had fallen foul to a wild animal attack, it took you almost a day to reach Asgard and upon arrival you were drained, but you still refused to show weakness. I remember how you told me the venture was sure to end badly but I didn't listen...I never listened. You took the blame for me too, telling Father that it had all been your idea, knowing that he would have punished me dearly from ignoring his wishes. You always did bear the brunt of my failures, spending time in the cells, or stocks, or even floggings. It hurts me to see how you were treated, because I was too stupid at the time to see what I was doing to you. You once told me you did it out of love, and protection, but I see now, I see how you did it so I would treat you as my equal, as one of my warriors, yet I never did. I got on with things as if nothing had occurred, only occasionally thanking you and allowing you to do it again 2 days later. I understand now, I was the worst brother you could possibly have had, I was blind to your sufferings, not just because you were so good at hiding them, but because I was too ignorant; I ignored you, I let you hide away in the library or your room, I did not even bother to ask you how your day had been. My friends were cruel to you, they picked on you, calling you names and calling you out on your unwillingness to fight. But the worst part is I was on their side, I never once defended you, never tried to stop them, I just let them carry on ridiculing you. I remember one time you came to me and told me Sif had accused you of not being my brother, not even the child of Frigga or Odin, and I turned on you, proclaiming how a son of Odin would not whimper and cry over such a small remark, and how maybe I didn't want a brother who was so scared to draw blood he ran away to his magic books. I always teased your choices, saying they were the cowards way out, even Sif was more manly than you. Now they say how you took the cowards way out, letting yourself fall into the void to run and hide from your punishment, but I do not believe that to be the reason you let go. I think you had given up hope, all these years you had wished for nothing more than acceptance, to be seen just as I was, by our family, our friends and all of Asgard, you clung on so hard but you never got it. I do not know why you did those things, why you let the Jotuns into Asgard, or why you tried to destroy Jotunheim, but I want to say they got out of hand, you lost control and panicked. You tried to kill me too, but that I have come to accept, I had it coming, though I did think it would be an enemy rather than you. You were angry and I do not blame you. I hope you have finally found peace, for it was something you could never find here, however hard you tried, I was always there to mess it up, somehow, someway. You would have been better on your own, no great oaf to look after, no bloodthirsty warriors to make jests out of you. Mother told me there was a chance you are still alive, though a large part of me wishes that isn't true, for I know what is in the void, you told me once. If you are alive, I beg you Loki, fight whatever it is that has a hold of you, for it will use it against you, it will rip it out of all proportions and tear you apart from the will lose your mind. I woke up again tonight, watching you fight me, yelling at me, at how much I have dissapointed you. You said that I loved Midgard more than I did you. What hurts me most is that a small part of me agreed, a dark part of my mind told me I would choose Jane over you. But I would not, I love Jane, I would take her as my wife, but you will always be by my side, as my brother.

So Dear Loki, please excuse my writing, I can't stop my hands from shaking. I miss you and nothing hurts like no you, and no one understands what we went through, you were strong, you were brave, you were loved...Dear Loki...

I wish I could start over, I wish we could have a second chance and I would make everything better. More than anything I want you to know we loved you, we were proud of you and you were ours. My brother, my spectacular brother...I wish you could come home.

Forever waiting, Thor.

Tears smeared the paper, making it crinkle and crack even more than it already did. Maybe he did feel better, maybe a little weight had gone from his shoulders. Making a mental note to write more letters when things got bad, he crawled back into bed, hoping that if he did see his brother again that night, it would be images of happiness, peace and love.

"Goodnight Loki."