Harry Potter felt the last person* leave like someone slamming the door to hell shut, although the door closed remarkably quietly. Harry was so angry he was shaking, and he took a deep breath, holding it in, and then letting it out.
Snape's eyes met Harry's, as he nodded firmly. His wand began to wave, drawing intricate lacework spells as he wove True Silence into the weft of the classroom's reality. After a single last gesture, he was done. "I should thank you, Potter, for saving your shouting for after class." Snape said gravely, continuing, "You know how I loathe petty distractions."
Of all the ways to greet a young man boiling over with anger! Harry was daunted, briefly, thinking that perhaps... And then, something shifted in Potter's face.
Quite simply, he didn't care.
"Why?!" He blasted, like a foghorn over a river, "Why did you have to single me out?" Harry said, his anger turning into action, arms gesturing with precise, tight movements as Harry's compulsion to act drove him to start circling Professor Snape.
A third of the way around, he wheeled on an ankle, looking up into Snape's eyes - with teeth bared. "I don't like the attention! I don't want the attention. I don't want anyone thinking I'm the next Dark Lord!"
All the winds deflated out of him, at that thought, as he looked at Snape, and suddenly asked, "I'm not - am I?" The question was quiet, uncertain - and an expression of faith. That Snape, of all people, would be honest - at least in this.
Snape's lips flicked up, for a split second, "I would find that to be rather farfetched. If you held me at wandpoint, and forced me to tell you who in that room would make the best candidate for prospective dark lord, I would have to name Neville Longbottom."
Harry's responding bark of laughter sounded about as split-psychotic as Sirius had on a bad day. "Then why'd you mention me? You did have a reason, didn't you?" Harry managed a look that would have suited Albus better - the 'I know you better than you know yourself' look.
"I always have a purpose. Nearly always have several." Snape said shortly.
"Can you tell me this one, at least?" Harry Potter asked, his anger still sizzling, but he was mastering it, holding it close and turning his voice away from the spitting his anger so dearly wanted.
"I suppose. Easy answers first." Snape said, taking on a teaching mien that Harry was well familiar with from Potions. Simply put, with word and gesture, Snape was saying, "don't interrupt."
"When I said that, what do you think people heard? Do you truly think that Miss Granger or Mister Weasley (indeed any of them) thought that you could use the Dark Arts successfully?" Snape asked, studying Harry Potter carefully.
"Of course, Ron didn't." Harry said, pausing uncertaintly, "I'm... not sure about Hermione. I could ask." This last, low sentence was said in the way that people walked to their own hanging.
"Every single one of your friends," Snape began, "No, even your enemies, and people who have scarcely heard of me, know what an antipathy I have nourished for you. And, from you, as well, I suppose."
Harry Potter looked at him, blinking slowly behind those thick glasses - his eyes slowly widening, "You don't think they'd believe you!"
"Why should they?" Snape said. "Do you want to hear another reason?"
Harry blinked. This would have been enough to satisfy him. But here Snape was, offering him... more. "Yes, sir." Harry responded, suppressing any stray eagerness. He did not want to look like a puppy.
"About ninety percent of the audience wouldn't think anything of what I said. And the other ten percent won't think hard about it today, either. There are, believe it or not, students who look up to me." Snape said.
Harry wasn't sure how to respond to that. Saying something that you expected to have someone think about later... That wasn't the way anyone he knew would think, could think, would plan on happening. "What, do you expect, might cause them to think about your words?"
Snape's lips twitched, again, "Why, they might become fully fledged practitioners of the Dark Arts."
*Granger. Ron doesn't know how to be quiet.
[a/n: Snape, what the hell are you doing? Enjoy speculating in the review!
Snape saw that Harry had a weakness. Then he started poking.]