It was the worst detention Neville ever had.

He had been caught painting Dumbledore's Army – Still Recruiting! on the walls. And not for the first or even the second time. At least the others had managed to run off before the Carrows caught them. He'd be the only one taken to the Headmaster this time – not that Snape could ever be considered the true Headmaster.

Neville stood stiffly in the Headmaster's office. He'd never seen it while it had still been Dumbledore's, but he stared straight ahead at the former Headmaster's – the true Headmaster's – portrait where it hung on the wall directly behind the huge, imposing desk. Dumbledore slept peacefully in his frame. No one had yet seen him wake. Snape's doing, no doubt. Neville hoped that, somehow, somewhere, the great man knew what he and the others were doing, and that he was proud of them.

"Three times, Longbottom," Snape said in that low, dangerous voice he had. The part of Neville that had always feared Snape, ever since that very first Potions lesson, wavered. But the larger part of him, the part that had faced down Bellatrix Lestrange in the Department of Mysteries, the part that stood with Harry even while Harry was missing, that part of him stayed defiant. Neville did not so much as flinch. "Three times you have been caught vandalizing these walls with graffiti. What does it take to penetrate that thick skull, I wonder?"

"Just crucio him, Snape. That'll teach him a lesson," Amycus Carrow said, and laughed.

Neville trembled despite himself. His entire life, he had witnessed the destruction that curse had wrought on his parents. Who were, as his grandmother often reminded him, so much stronger than he was. The Carrows had put him under the curse several times already, and each time, the agony of it made him long for the freedom of his parents' madness. And then, once the curse finally lifted, his guilt for having such thoughts overwhelmed him, until he felt worse than he had while under its effects.

"And yet the lesson evidently did not take the first time, nor the second," Snape replied smoothly. "No, I think a more… practical punishment is in order. I understand, Amycus, that Longbottom has not yet managed to cast a successful crucio himself? Not surprising, as he has always been weak. Yes, I have exactly the punishment for him. You may leave us."

The Carrows left reluctantly, Neville could see. Clearly, they wanted to witness whatever Snape's "practical" punishment would be. No doubt it would be especially foul.

Snape steepled his fingers together. "Do you hate me, Longbottom?"

Neville did not respond. The answer was yes, of course he hated the man, but he refused to play whatever game Snape wanted him to play. Nevertheless, Snape smirked as if he knew the answer.

"Yes, of course you do. The professor who has always pointed out your abundant flaws. The Death Eater. Dumbledore's murderer." If possible, Snape's smirk grew even nastier. "You openly defy my authority, scribbling childish nonsense on the walls of this castle. Meaningless rubbish, making no real difference. I doubt you have the nerve or the ability to do anything more… constructive, but let us test that, shall we?

"While doubtless your failure to cast the cruciatus curse is due to your own abundant deficiencies, the targets chosen by my colleagues may not have been optimal for your initial instruction. Finnegan and Brown? No, you must truly wish harm on someone to cast the curse. So let us have you try on a target you no doubt deem worthy of your ire.

"Take out your wand, Longbottom, and case the cruciatus curse on me. Only the cruciatus. I shall not resist. Cast it, if you truly wish to harm me, if this is not merely the misguided rebellion of a weak and ignorant child."

Neville stared at him in mute shock. Surely, surely, he had misheard.

"Well, Longbottom? Not even going to raise your wand against me?" came the hated, jeering voice.

This was his chance. He could strike a blow for Dumbledore's Army. He could at last give Snape what he deserved.

For a single, glorious moment, Neville imagined Snape writhing on the floor as he had, as his friends had, imagined that smooth voice going raw as his screams tore his throat, imagined that smirking face contorted in agony. Snape would finally, finally, get what he deserved for killing Dumbledore, for letting students be tortured, for everything. It wouldn't be vengeance; it would be justice.

It was a beautiful thought.

Neville raised his wand and pointed it at that horrible, hateful face. His hand began to tremble, but he gripped his wand tighter as he focused. "Cru-" he began, and Snape made no move to block the curse. He did not rise from his seat to dodge. He sat motionless in the great chair behind the desk, that cruel smirk still on his face.

And then the moment passed, and Neville's stomach clenched. He cut himself off mid-curse, feeling suddenly nauseous. It took all of his willpower not to vomit all over the floor of the office. Although that would serve the murdering bastard right, he thought, somewhat hysterically.

His hand felt hot and sticky with sweat as he gripped his wand with white-knuckled fingers. He looked down at it as if from far away. What had he been doing? This was his chance. This was the DA's chance. What were the odds that he'd ever get another? Would he really –

"No."

The word surprised even him. It came out soft and more than a little shaky.

"I beg your pardon?" Snape asked, and Neville could practically feel the icy disdain dripping from his tone.

"No," Neville said again, more firmly this time. He lowered his wand.

There was a glint of something like triumph in those hated black eyes. "As I suspected. Too cowardly and weak to strike against a man you purport to hate. Remember this, when you are next tempted to your meaningless acts of vandalism. Remember that when you had the opportunity to hurt me, you lacked the will to act. What will your co-conspirators say, when you tell them? Do you think they will still respect you? When they find out that, in the end, all you can do is write worthless words about a dead man's army? Will they ever forgive you? Will you ever forgive yourself?"

"Why?" Neville managed to rasp. "Why did you do this?"

"Why?" Snape's voice sounded amused, damn him. "Because either way, I knew I would win. If you successfully cast the spell, then I would have finally managed to teach you, something that I had long-since despaired of doing. Any spell once cast is easier the second time, after all. And if you failed, as I had little doubt you would, then you would see for yourself how weak and hollow your little rebellion is."

It was a somber and shaken Neville who returned to Gryffindor Tower. Ginny and Seamus asked him what happened, but he merely shook his head mutely and went up to bed. He ignored their worried glances, their whispers about what might have happened. Lying on his bed, he stared unseeing at the curtains.

Neville knew that he would never tell his friends that he had had a chance to curse Snape but hadn't taken it. He knew they wouldn't understand. It was too tempting a thought, to imagine Snape suffering under his wand, paying for his crimes.

It was too tempting.

For a moment, Neville had almost cast the cruciatus curse. For a moment, he had almost cast the curse that had destroyed his parents. For a moment, he had almost betrayed everything he believed in.

In that moment, Snape had won, and Neville had lost.

Neville hadn't done it. He hadn't given in. He hadn't betrayed his ideals.

But he had wanted to.

It was the worst detention Neville ever had.

A/N: Please review!