Disclaimer: These characters belong to the wonderful JKR. And I'm wearing lawsuit repellent. $6.95 at K-Mart. :P

An incident in Potions class

"At least my mum wasn't a filthy mudblood!" Draco hissed at Harry.
Before Ron and Harry could leap for the Syltherin's throat, an icy voice cut though the room like a sword.
"What did you just say?" Professor Snape snapped as he whirled around and stalked towards Draco. His teeth were bared and his normally cold eyes glowed with anger.
"I-said-um-well, sir-it wasn't-," the boy sputtered.
"He called Harry's mum a mudblood, sir!" Ron chimed in, glaring at Draco.
"SILENCE BOY!" Snape thundered at Weasley, never taking his eyes off Draco. "Now," he half-whispered, addressing Draco. "What did you just say?"
There was no mistaking the malice in the silky voice. Draco turned even paler, if it as possible to believe that, and slid down in his chair. His lowered his eyes from the gaunt face before him and muttered
"I called Potter's mum a mudblood sir. But-"
"ENOUGH! GET OUT OF MY SIGHT! ONE HUNDRED POINTS FROM SYLTHERIN!" Snape boomed, louder than Harry had ever heard him yell before.
Draco looked like he was about to faint. He stood shakily from his chair and managed to stumble out of the dark dungeon room. Snape stood there in front of Malfoy's desk, gripping the edge of it so hard his knuckles were white and the wood threatened to splinter. For a good long minute Snape just stared down at the desk, a look of absolute fury frozen on his face. Finally he shut his eyes tightly and heaved a silent sigh. He released the desk and looked around him, at his class that was now staring at him openmouthed. They had never seen him punish a Syltherin before. He glared at the class.
"Get back to work!"
Everyone bent their heads back over their cauldrons, hurriedly stirring in ingredients, and hoping that their potion wasn't spoiled because they'd neglected it in favor of gawking at the little scene that had just taken place. Everyone but Harry that is, who still stared at Snape like he'd just grown another head. He thought Snape hated him. Had his professor just defended his mother?...no, Harry thought. Impossible.
Snape turned his gaze to Harry. "I said, back to work, Potter. You don't get special treatment because of your celebrity status," he sneered. But for a brief moment, a fraction of a second, something broke through the emptiness of Snape's eyes. Harry saw something in those black eyes that frequently appeared in his own when he thought of his dead mother. In those cold, dead, eyes, like tunnels of darkness, Harry saw a flash of pain.