We'll fast forward to a few years later
And no one knows except the both of us
And I have honoured your request for silence
And you've washed your hands clean of this.
Hands Clean, by Alanis Morissette
As Severus walked to Hermione's house, a bottle of deep red wine in hand, he thought. This, in itself, wasn't at all an unusual occurrence. Severus thought constantly, whenever he was spared a moment of time in relative peace he would use it thinking feverishly about the flaws in his latest idea, or different potions, or thinking about runes that could be used to manipulate the meaning of a substance. Severus Snape did not have epiphanies—he simply thought constantly, and the sheer volume of his firing neurons resulted in remarkable results.
No, the unusual thing about this was what he was thinking about. He was imagining the future, something he hadn't done in years. When your future is, more likely that not, soon going to cease to exist, it's not something you waste much of your time daydreaming about.
But, he decided as he walked, pacing carefully down the dirt road, this… thing with Hermione warranted at least a little bit of forethought.
He wanted her. This was undisputable, and he had known for weeks. Nor was it a question of how much he wanted her, or for how long he would. He already knew, with the perfect lack of doubt he had always had when it came to his own mind, that it was desperately, and for as long as possible.
So then, the problem that he was stumbling upon was that it seemed very, very unlikely that a woman, not much more than a girl, really, would want him in the same way.
It could be secret, his mind suggested. Keep it quiet and then if it fails, no one will know. But the flaw in that was that he would know, and she would know. Even if no one found out, it would be devastating.
Years from now, if they tried and failed, their relationship probably wouldn't register as much but a distant memory. She had so many chances, so many opportunities stretching ahead of her. This was his last big one, his last that mattered.
But he had reached her doorstep, and resolutely, though he was still conflicted, he raised his hand to knock.