Disclaimer I don't own anything Harry Potter, Jo Rowling does. This was originally written in answer to a sorting hat question of "What would you do if you faced Voldemort?" A much shorter version of this story is what came out.
Sacrifice
I have been sent here with a clear purpose. I knew it would happen. This is my sacrifice.
I know he is here, unseen. My heart pounds with anticipation and my lungs refuse to accept air with an instinct of fear and survival, an instinct I try to suppress for I know survival will not be my fate. I knew this when I took my mission. I turn at the sound of a shuffle behind me. I am a toy and he is playing with me.
An unknown curse is thrown from behind me and knocks me forward. I yell in panic, draw my wand and accidentally drop it on the floor. My mind goes blank. I immediately forget everything I had learned from all the years of Defense Against the Dark Arts classes. I recover my wand and duck behind something large and solid, a pointless attempt at hiding. I try to focus my attentions to what I'd learned in the DA with Harry. Focus, I command myself. I try to throw him a curse but fail because I lack it in my heart to want to hurt or kill anybody...even the Dark Lord himself.
He knows this and laughs at my half-hearted attempt to cause pain. I know my fate but I will not go down without a fight. He steps into a sliver of light provided by a thin window. I know I need to focus and try to force away the instinctive fear that is creeping into me. The mere sight of him brings my soul crying for mercy. I refuse to cower in his presence. I refuse to surrender. This is my sacrifice.
I dodge the green light that was meant to have killed me. Too soon, I tell myself. I successfully hit him with a jinx that has no effect. I am hit with the Cruciatus curse. My head feels as though it is splitting in two. Every muscle feels as though it is being ripped from my body. He is in my head. I can feel him searching my mind. Somebody, please, stop this! I try to defend myself but my words only form into an incoherent scream of pain. Is this what I have come to? To relive the fate of my parents?
He ends the spell and I feel my body relax against the cold ground. I am still breathing, though I know my breaths are shallow and close to stopping. This is the end. Too soon, I tell myself. I have failed my mission. I have failed.
He looms over me, studying me with his burning red eyes and a twisted, snake-like smile. He is laughing. I lie on my side in pain, cradling my throbbing head, inhaling what might be my last few breaths of life. I see from the opposite end of the long room, members of the Order entering, wands drawn. They have arrived and I know that I have, in fact, succeeded in my mission—to distract Voldemort's attentions, to keep him from escaping into the darkness again, to keep him in one location until my friends could arrive as a group and overtake him, defeating him. This is my sacrifice. He does not see them enter.
He levels his wand to my heart, ready to finish my suffering with the inevitable Avada Kedavra curse. I look again at my friends for the last time. Harry leads the group with determination in his eyes. He looks to me, I see his fear, afraid he might be too late.
I take what I know will be my last breath but I am proud in knowing my death is not in vain. I hear Voldemort's words as he begins the death curse. I smile.
I hear Harry's shouting words, but my light is quickly fading. Voldemort turns to face his enemy, a raven-haired, seventeen year old boy with eyes of emerald green. I feel the blackness covering me like a warm blanket on a frosty December night. I know no more.
~*~
The End.