A/N—One-shot, though I might make an epilogue. Doubt it, though. Please read and review!

You Were Wrong

"The time will come, and you must be ready. Do I have your word?" I gave him a look of pure contempt. Had he any idea what he was asking of me?

"You can't be—" He shook his head before cutting me off with that obnoxiously calm voice of his.

"Your word, Severus." Damn you, old fool. His twinkling eyes and lighthearted take on the situation only made me angrier. 'You will see your mistake before the end' I thought to myself. You're wrong this time, wrong about me. Even that idiot Potter can tell you that. As if on cue, the truant boy stalks into Dumbledore's office.

"Yes, you have my word." I gave him one last disgusted look and left.

X.X

Lord Voldemort stood over the dead Tonks. She, one of the last of the order, represented the fading hope the wizarding world had against a merciless tyrant. As the Order of the Phoenix's headquarters burned to the ground, swarmed by the countless Death Eaters launching unforgivables in every which way, I couldn't help but laugh in irony. You were wrong Dumbledore.

X.X

The Dark Mark hovered over Hogwarts as I rushed to the top of the astronomy tower. 'Malfoy,' I thought angrily. I made an unbreakable vow to his mother—an unbreakable vow—and yet he still didn't tell me about the Room of Requirement. I just hoped I wasn't too late. As I crashed through the doors, I saw something I thought I'd never see.

Dumbledore was at the mercy of three Death Eaters and Draco Malfoy. Everyone in the room turned to stare at me—it was Dumbledore's eyes that I only cared to look into at the moment. His pleading eyes, still twinkling with a goodness that made me sick. Draco hovered over him with a trembling arm holding a wand that seemed ready to fall at any moment. The fool couldn't do it! After everything, after all his planning, he couldn't kill him!

"We've got a problem, Severus," said Amycus. "The boy doesn't seem able to--"

"Severus," Dumbledore pleaded. Dumbledore begging was an unsettling sight, but if I didn't kill him, one of the others would, and the Dark Lord would give them the credit. My face contorted into one of pure hatred and contempt. 'You're wrong,' I silently told him.

"Severus…please…" he replied. You fool. The clock was ticking, and hesitation meant death.

"Avada Kedavra!" The killing curse hit him squarely in his chest as the greatest wizard who ever lived fell at my hands. You were wrong, Dumbledore.

X.X

"Voldemort!" said that defiant voice I recognized so well. From the flames arose a figure with a nasty, lightning-shaped scar on his forehead. He was alone, which meant that his friends were already dead…or worse.

"Harry Potter. For far too long you have stood in my way. I will personally collect your debt." The Dark Lord raised up his wand, but Harry was quicker.

"Avad—" Potter, you fool. You still haven't learned the art of Occulemency! Then again, who could have taught him with Dumbledore gone? His wand was out of his hand before he even finished the first word. Voldemort gave a terrible laugh before launching his own Avada Kedavra at Harry. His mother's blood could protect him no longer. He was dead before he hit the ground.

He died because you were wrong, Dumbledore. You were wrong about me. I'm not the great wizard you thought I'd become—I destroyed the Horcruxes when I found their location, sure, but the Dark Lord is more immortal now than ever. The Order didn't need a spy to defeat Voldemort—they needed a leader and a guide. They needed you, Dumbledore.

As Voldemort stood cackling alone over the dead body of Harry Potter, I saw something for the first time in my life. He wasn't prepared—wasn't cautious—because he had heard the first part of the Prophecy. He thought himself invincible now. And he would have been, had I, who through and through was--and always will be--Dumbledore's man, not been standing behind him. At long last I saw the wisdom in Dumbledore's words. In war, sacrifices must be made. I raised my wand and stared at the Dark Lord, still oblivious to my presence.

"Avada Kedavra!" He turned around far too late as the green light jetted straight into him. The last piece of his soul writhed before dying. I stood in shock and wonder as the Death Eaters all stared at me. I was so shocked by my revelation that I didn't see twenty green jets of light all coming my way at the same time. Somehow, someway…you were right, Dumbledore.