Black's Night
Faint moonlight fell upon the grey stone floor of the cell, the bars across the high window dividing it into long, narrow lines as it passed through the small aperture. It was a cold glow; one to match the frigid atmosphere that hung over the prison as the cold seeped in and frost took root deep in the prisoners' souls. Hope had died for them, and with it any warmth its flame could bring.
The cell's occupant sat on the floor with his back against the wall, feeling its hard surface against his spine. The light didn't reach him, but he made no move towards it, instead sitting passively and allowing the shadows to obscure his face as if wished he could become lost in the dark. True to his name, the blackness was where he had found his place.
In the distance he could hear screams: an unsettling symphony of other prisoners crying out in anguish. The days were usually silent, but the nights were when the torments of the Dementors were at their worst. Outward appearances may have given the opposite impression, but Sirius felt it as keenly as any of the others. He felt the chill of their presence, the way their cold breeze would blow the image of James and Lily's dead bodies in front of his eyes and reopen the knife wound of Peter's betrayal twisting in his back...
It drained the happiness from him - what little there was left of it to begin with - but there their power ended. His conscience was clear. There was no guilt to fill the vacuum left behind when all joy was sucked out. That may not have brought him comfort, but it brought him clarity. He could see clearly, unobstructed by the bitter rage at the injustice he had been dealt, and knew that it was Peter who deserved to be in here and not him.
As he gazed towards the clear lines of light upon the floor, they illuminated Sirius' vision of what would come: he would wait, for however long it took for an opportunity to escape to present itself, and he would get out of here and he would find Peter and he would have revenge. Revenge for James and Lily and Harry and himself, one way or another.
That was the thought that kept him going through the long nights when the power of the Dementors became almost too much to bear, his focus providing a steadfast glue that held his mind together. The light was there in the distance, and he would see out the darkness to reach it.
But then the clouds passed over the moon, the light died, and Sirius was left in blackness once more.
