hi :D
This is kinda based on this song .com/watch?v=R6-XYJ9fVyI
Warning: Angst. Implied Sirius&Remus.
Disclaimer: i obviously don't own Harry Potter, if i did, there would be yaoi in it and neither Sirius nor Lupin would die.

I was sitting down, alone in the cold stone floor of my improvised cell, wandering through my mind. I sighed heavily for the umpteenth time, I've already lost track of the sigh count, with no particular reason while looking through the small window; all i could see was the night sky and the moon. The full moon. Moony...I couldn't help thinking of you. That's when I decided to write. I grabbed the parchment and the quill they allowed me to have and I started writing:

Dear Moony and Prongs Jr.:
By the time you read this letter, I'll probably be dead.

Dead. That word suddenly seemed so big and mighty, almost impossible for me to say, but, sadly, it was true.

Three days. This is a future I cannot avoid.

Oh, Merlin, in three days I'll be dead. Well, in theory, not dead, actually, it was a fate worse than Death: Lying on the ground cold and lifeless and with a pretty Dementor all over me. Yes, I was sentenced to have my soul sucked out by one of those hideous black monsters. The Dementor's Kiss.

I'm having trouble writing words I've written many times before.

I confess as I notice I'm shaking, my hands tremble badly and, while attempting to dip my quill in the ink bottle, I spill it all over the parchment. I crumple it, tear it apart and finally throw away, taking another one and starting again. I try to calm myself down before writing again.

"How should I spend the rest of my 70 hour life?" I asked myself as I picked up my quill.

I figured out writing would be the best thing to do, in that way, I could at least leave behind some last words for the two people that meant the world to me: my best friend/lover and my Godson, that way they won't feel like I'm gone without saying goodbye, for I don't want to go away the way I did thirteen years ago, when I was taken to Azkaban.

I don't have anything to say, really. I just write whatever comes to me.

I doubt my letter will make a lot of sense, because I do write whatever comes to me. Bits of memories shared with either of them, random thoughts that cross my mind, even fragments of muggle and wizarding songs. Sometimes, I re-read the letter and I'm tempted to throw it away for it is full of trivial things and it's quite senseless, but either way I don't do it because I know that soon enough this will be the only remain of my existence.

The next thing I know: two days have gone by; I've spent all this time writing my letter for you…

I have been writing for a long time, actually, that is pretty much everything I do, because I'm not allowed to do much. I eat, I write, I sleep for a while, I keep on writing. I can't believe that I have only one more day in this Earth, I'm a young man, I could have lived a long, nice life if I was not fated to die at age 34. I could have done so many things... I like to think that maybe, if my name had been somehow cleared, I could have lived with Moony an Harry a dreamed life and then die out when I turned old and gray, still having both of them by my side. But well, you can't always get what you wanted.

The fear that was inside my heart is calm and quiet. It's as if I were watching a dream.

I wrote down. Well, it was partially true. When i was first told about my terrible fate, I was terrified, for there is nothing worse than the Dementor's Kiss. But then, I thought that perhaps Azkaban in even worse, and I survived Azkaban, bloody hell, I escaped Azkaban! so maybe, just maybe, the Dementor's Kiss would not be as bad; I mean, few seconds or even a minute of suffering and then... Nothing but darkness and numbness. I kept that in mind and slowly my fear calmed down.

Out there, under the sky, what are you watching and what are you thinking?

I wondered even though I knew I would never find out the answer to those questions. What are you doing in this exact moment, my Moony? Are you crying for losing me? I hope not, 'cause I have never been able to see you cry, let alone making you cry, though I know you've shed tears for me through all my years in Azkaban.
And you, Harry? What do you think of this man who turned from dangerous killer to loving godfather in matter of hours?

This 24 hour life is too short to go by your side.

I knew that I could ask Dumbledore to tell the guards to grant me one last wish. And I would ask for seeing both Moony and Harry, have a last kiss, a last hug, a last "I'm sorry" and be ready to go, but it would be too hard for me to see them and say goodbye, I've always hated goodbyes.

It is sad, but at the same time I am relieved. I find myself feeling relief that I will never see you again, because, if I did, then everything inside me would come loose.

I simply did not want them to see me cry.

I kept on writting about pretty much everything, almost without me noticing, time elapsed and now I was an hour away from the time I was scheduled to get kissed. I looked out through the small window and saw the bluest and prettiest sky I can remember. "Well, at least my last day alive was a beautiful one..." I thought before writing down some if the last lines of my long farewell letter.

It's hard to believe that my world is going to end in a few minutes. This fine feeling of the beautiful blue sky is almost too bright for me even if I close my eyes. If tears come flowing out it's probably because of that.

Feeling imminent death over me made me feel like crying, all the calm and peaceful feeling flew through the window as i realized I'd be dead in less than an hour.

Even if I have a little time left, I'm going to live my life. Even if lose everything, I'll always know I lived my life.
All my love,
Padfoot
(Sirius Black)

I finished writing and then everything else blurred out. Next thing I knew, it was time.

I was taken out of my cell. There were many Aurors, to make sure i would not escape, obviously the Dementor and a small congregation of Hogwarts teachers. Among them I saw them; Remus was standing there, holding Harry close.

I felt my heart sink low; I did not want them to see life sucked out of me. A single tear rolled from my eyes as I locked my eyes on them. "Please... Go..." I thought as I saw the Dementor coming closer.

It removed its hood. I closed my eyes and took a deep breath as I felt fear wash all over me. I started feeling weak, a cry escaping from my mouth as the world blurred out. I shot a last glance at Remus and Harry; they both looked pained, holding tight to each other as they looked at me.

"Expecto Patronum!" I heard them cry before everything faded into darkness for me.