Undetermined timeline, but after fifth year. Just a plot bunny the last few days that I thought I would share.

Hermione didn't know what Professor McGonagall had said to Harry. She had come to the Gryffindor table several minutes ago and put her hand on Harry's shoulder and after a quick whisper in his ear had hurriedly taken him out of the Great Hall. When he came back in the door, Hermione noted his pale face, clenched fists, and blotchy cheeks and if Harry had been anyone else, she would have said he had been quietly crying. McGonagall stood behind him, watching him with concern.

Harry began to slowly making his way back to his seat, his steps faltering and his mind clearly otherwise occupied, when a jeer rang out from the Slytherin table.

"Hey Scarhead, care to join us for lunch? We're having fried chicken!"

Harry stopped and something rippled across his face and time seemed to slow. Hermione later described it like the world itself had stopped to take a breath. And released it with a giant roar. Hermione remembered seeing

TICK

Professor McGonagall's face twisting furiously and the beginnings of a shout of "50 points" at the Slytherin table.

Professor Snape trying to rush past Professor McGonagall towards the Slytherin table.

Harry's wand appearing in his hand as if summoned.

TOCK

Professor McGonagall finishing her cry of "from Slytherin!"

Professor Snape breaking into a broken run in the Great Hall.

Professor Dumbledore standing up from his seat at the teachers' table.

Harry leveling his wand at Draco Malfoy's place at the Slytherin table.

... and then time resumed.

Harry destroyed over a quarter of the Slytherin wooden table with a single unspoken spell. Shards of plates and splinters of wood sprayed through the air as Harry advanced on the entire Slytherin table. Harry moved rapidly but unhurriedly through the debris, stepping around stumbling students' bodies as they fell back from the wreckage of their lunch. As he got to a sprawling Draco Malfoy, Harry knelt and smashed his fist into Malfoy's face. Not a punch from a schoolyard fight, but instead a blow with everything Harry could bring to bear. As Malfoy's head twisted rapidly to one side, Harry stood and kicked at his ribs, then dropped his foot heavily and repeatedly on Malfoy's chest.

Hermione truly believed she was going to watch Harry kill Malfoy as she heard the wet snaps and crunch of bone from each kick and punch. Her face screwed up with revulsion to hear Draco's feeble but anguished cries of pain. She was literally frozen to her seat, as was the rest of the school, even the Slytherins who began giving Harry a very wide berth. Even Professor Dumbledore stood with his mouth hanging open.

Professor Snape got close enough to Harry and bellowed "Potter!", his wand out and aimed towards Harry. That turned Harry towards Snape and Hermione almost screamed at the cold look on Harry's face. It apparently gave Professor Snape a moment of pause as well, long enough for Harry to banish him into a wall, knocking Professor Snape unconscious.

The DA members Harry had worked with for so long finally broke free of the destruction-inflicted trance and raced to pull Harry back from the bleeding boy. The Slytherins had all retreated from Harry. It was just Harry and Draco, and Draco crying piteously and weakly, pink bubbles frothing out of the side of his mouth.

As Ron and then Dean and Neville got to Harry and tried to pull him away, Harry finally stepped back and shrugged their hands away.

He was looking down at Draco, his wand aimed directly at Draco's chest. And the whole hall heard his next words against the backdrop of bubbling breaths.

"She was my first friend, Draco. What did you think I would do? Listen to your laugh and do nothing?"

Professor Dumbledore finally managed to get words out. "Harry, what have you done?"

Harry turned pitiless green eyes to Dumbledore, though his wand was unshakingly centered on Draco's chest. "The question should have been, 'Harry, what are you doing?' My answer would have been 'Putting down a rabid dog'", he said, in an equally pitiless and cold voice.

Professor Dumbledore stammered out, "But Harry... the governors, the Ministry! You'll have to be expelled for this, at a minimum! The Malfoy's may try prison charges as well! What were you thinking?"

Harry's voice gave everyone a shiver. "I was thinking that death in this war has been remarkably one-sided. I was thinking that I'm tired of it always being me and mine with a bullseye on my chest. That ended the minute they killed Hedwig and Malfoy taunted me with her suffering. 'They that sow the wind, shall reap the whirlwind' I believe is the saying. Tom and Snape's little pet is about to bring in his harvest. And then we'll see about the rest of the Death Eaters."

Harry dropped a single white feather, charred around the edges, to the floor.

"Reducto."