I originally wrote this for school, because my English teacher assigned us to write a story about the six seconds before something happens about 750 words in length. It was supposed to be less action and more imagery, figurative language, etc. to describe our feelings and fears and whatnot. Well, I asked her if I could do the six seconds before Snape killed Dumbledore, and she let me. And I decided I'd share it as a one-shot on here, since it pretty much is fanfiction.

For those of you that read my other fic, in which I'm rewriting the HP series from Snape's point of view, Vesperra is nonexistent in this. I couldn't include even a mention of her, because my English teacher would have been confused. Anyway, I'm sorry this A/N is so long. Enjoy the one-shot!

This is happening. There's no backing out now. I must do this. It was a thought that had occurred to me several times in the past year, though never this immediately, and never this seriously. Like an iron weight, it had been growing heavier on my chest, forcing my heart to sink deeper and deeper into its shroud of darkness. And now, I could not resist anymore, because the time had come. I had to let it sink all the way.

I could not help, as I ascended the last of the stairs, but desire to turn time and return to the year before, when this task hadn't even been necessary, or several months ago, when the inevitability of it had seemed so far away, or even yesterday. Any day before this. The desire turned me into a child once more—into my teenage self, when, as a rookie Death Eater, I could not bring myself to kill the Dark Lord's victims.

But this was not truly one of the Dark Lord's victims. Albus Dumbledore had planned his death far before this day, and the old man wanted me, the one questionable spy of his, teetering on the edge of the Rebellion and the Death Eaters as far as others saw it, to do it. I had been sucked into this scheme of his, just like I had so many years ago. Though that man has used me for years, he has been my mentor and the closest thing I could consider a friend in years—and he asks me to kill him? No, I don't care how you feel about this, Severus. I know you feel as though you've now wasted much of your life as my puppet, protecting Harry for me when I knew he had to die in the end. But you've promised, and I expect you to live up to that and risk harming your own soul. Just risk your life and everything you care about. That's how it was.

So why was I still walking forward, and not backing down, letting Draco do it? Why was I still adhering to Dumbledore's plans, when I felt no true loyalty to him? I suppose that, however much I loathed it, I knew that carrying out this plan would ultimately result in the destruction of the Dark Lord, after all the incessant pain that I have suffered and was destined to suffer in the future. Above all, that's what I wanted—for the man that had killed Lily Evans to be dead. That's what I have lived for.

The moments ticked by, as I stood on the Astronomy tower, counting down not only the death of the uncharacteristically withered man before me, but also my role as a spy. I knew that, as soon as the Order of the Phoenix, fighting several floors below, discovered what I had done, there would be no question of my loyalties for anyone except me. This was my own demise as well, because I finally had to succumb to the Dark powers calling me out by my name, no matter how much I wished I did not have to answer to them after the sacrifice that Lily made all those years ago. But I would keep up the façade until the very end, if only for her. It was all for her.

As I came to terms with the fact that the final seconds were upon me, my vision rounded out like a fisheye lens, allowing me only to focus through my gaze of pain and hatred on Dumbledore. Behind me, the Death Eaters were impatient, and Draco was clearly frightened beyond measure. Above, the Dark Mark glittered horribly on the sky, burning green fire that illuminated the Astronomy Tower, mimicking the smaller, black one on my arm that burned only in my mind. Physical pain would have been preferable to this.

Each moment of hesitation lasted what seemed like forever, and I could not decide whether I wanted time to slow to a stop or speed up. No one else on the tower could hear my heart beat, sinking deeper into my chest with each pound. The words "Severus, please" echoed alongside the pounding of my heart, and darkness pressed in on all sides.

I locked eyes with my former mentor, and my face contorted into one of absolute hatred. I raised my wand, and the pounding stopped.