Disclaimer: Not mine.
The room is a giant mirror. The walls, the ceiling, the floor, it's all made of panes of mirrored glass. He doesn't know why, and he hates it. Hates his reflection, his lying face. He is not like the others, the arrogant people of his House. He isn't Bella, who loves causing pain, or Narcissa, who loves feeling like she's better than everyone else. And he's certainly no Sirius or Andromeda, because he's never learned to fight back. He is his parents' favorite, because he conforms, because he doesn't have the guts to speak for himself. He hates himself. He always has.
He's back again, looking at himself reflected a thousand times. "What's the point?" he yells wildly. What is the point of seeing his reflection? He knows what he looks like; why does he need to see himself? He doesn't understand; but then, he doesn't seem to understand much of anything.
He comes back, the day he leaves school forever. He's been wearing long sleeves all the time - he has to now. He enters the room and all he sees is that mark, shimmering in the mirrored walls, the one that has been burned into his flesh. His reflection is gone; now that he thinks about it, it had seemed to fade a little more each time he came in. But still he does not understand. All he knows is that he can't stand the sight of that brand, his Dark Mark. With a feral scream, he smashes his hands into the walls, shattering the mirrors, blood pouring from his hands. He has a lot of explaining to do when he goes to the hospital wing, and he's sure the nurse didn't believe his story.
And then, only a few scant years later, he lays dying, for trying to escape the trouble he'd gotten into, or so his killer - his own cousin! - thinks. Bella thinks he's just a coward. They all do. The other Death Eaters, all his old 'friends' from school, even the brother he secretly wished to be. But he's not as weak as they all think, not as foolish. He did what the Dark Lord would have never expected and has hopefully weakened the man he once called Master. And finally he knows why the room was always a mirror, why his reflection faded. He needed to see himself, to be himself, beyond his act, behind the mask he wore. And he knows if he were to return now, his image would be reflected back at him, clear and strong, because he knows who he is. He has broken free, even though to do so was fatal. He is free, and for the first time in what feels like ages, he doesn't hate himself.
A/N: OK, this is based off a challenge I learned about months ago, and I wrote this then, but I never got around to posting it. I found the challenge in the fics The Room of Requirement by Musey Muse and in Blood Red Perfection by Crying Sorceress. I highly recommend both fics. Oh, and in case anyone missed it, though I'm not sure how, yes, I wrote about Regulus Black. I was going to do Blaise Zabini, but I couldn't get the mirror concept to work with him...