"Do not," he hissed, his voice soft, deadly, icy, "do not even dare to blame yourself for something the Dark Lord initiated." Harry breathed in sharply, trying to lean back inconspicuously as Snape advanced further. "They made their choice. Do not be so arrogant as to assume that you are able to influence your peers, let alone your betters." He paused in his tirade long enough to sneer, presumably at the memory of Sirius.
Harry blinked at him, completely nonplussed. Snape continued to glare down at him from his impressive height. "Do I make myself clear, Mr. Potter?" Harry nodded, just because it was the only action he could think of doing at that point.
"Do you understand that which I'm trying to convey?" Harry frowned lightly, but nodded at any rate. Snape's nostrils flared and he drew his robes tighter around himself, but he did not move from where he stood, towering over the Gryffindor.
"Blaming yourself induces bitterness and indifference. We do not want that in our Savior, now do we?" Snape's voice contained the usual bite, but to Harry it seemed as though there were undertones of carefully concealed anxiety.
"Speaking from experience, sir?" Harry asked, dully. He wasn't prepared for the flash of anger that flew through Snape's eyes before disappearing under a mask of stoicism.
"Rather."
"Oh." He fell silent and focused on his shoes instead, wishing that he had the courage to ask to be dismissed. Some Gryffindor. A long-suffering sigh from above him drew him out of his intense studying of his scuffed laces.
"Blaming yourself for something that is not you fault gives the impression that you can change the fact. This impression drives you to seek means you would not consider otherwise." Snape's face was carefully blank, his eyes unfocused. Harry nodded, not certain if Snape had seen him or not. He thought he knew what Snape was talking about. Means otherwise unconsidered? It's not hard to fathom the implications behind those words.
Snape looked down at him again, seeming almost surprised to see him there. Harry looked away again, not meeting his gaze, eliciting a scowl that went unnoticed.
"Mr. Potter, if I ever catch you saying anything of the sort, if I ever catch you thinking anything of the sort, if I hear news from trustworthy source of you saying and thinking anything of the sort, ever again, it'll be 100 points from Gryffindor." Harry's head snapped up in alarm, anger and confusion battling within him.
"Do I make myself clear?"
"Yes sir."
"Dismissed."
Harry paused outside the door, shutting it lightly. Dumbledore's words floated across his mind.
'When you feel ready, these sessions should be terminated, they will be.'
Ready for what, the Headmaster hadn't answered him. But with a slight smile, he set off towards the ugly stone gargoyle.