Author's Note: Written for the '1000 Prompt Competition' Challenge by Jenna McCoy on the HPFC forum. Yes, this is AU. My prompts were "incorrigible" and "Sometimes insanity is the only alternative."

Blaise was ninety percent sure that Professor Snape was about to commit murder.

After meeting Draco Black at the Welcome Feast, Blaise had quickly learned that his new best friend was irredeemably Slytherin. In their first week at Hogwarts, Draco had come up with a novel method of cheating at Astronomy, had snuck out after curfew twice without being caught, and had adopted one of the Hogwarts house-elves for his own personal use – Blaise still wasn't sure exactly how. Draco had also made a big deal of snubbing the students of their rival house, Gryffindor. So it came as rather a shock to Blaise when they went to their first double Potions class and Draco sat with one of the Gryffindors.

That Gryffindor was Draco's brother. Blaise learned that Harry Black was every bit as sneaky, clever, and arrogant as Draco. The difference, or so Blaise eventually decided, was that Harry had a sense of righteousness about the whole thing, whereas Draco acknowledged that he was doing something wrong, but he didn't care.

It was all very exciting, to be sure, but nothing was more exciting than the two of them together in Potions class. Between them, they seemed to have made it their goal to annoy the professor as much as possible, or perhaps they simply wanted to get a detention every week. Blaise had yet to solve the mystery of how the Blacks' minds worked, so he really couldn't say if they were masochistic or just clueless.

"But sir," Draco was saying, his hand in the air, "wouldn't it be better to use ten salamander eggs?"

This was about the fifth comment made by one of the Blacks since class started, and Blaise could see that Snape's patience was quickly wearing thin. The professor closed his eyes briefly and then opened them to respond in a clipped voice.

"No, it would not."

"But the eggs are so small," Draco persisted. "Nine can't possibly be enough."

"Mr. Black, do you believe yourself to be, at eleven, more clever than the master who invented this potion two hundred years ago?" Snape was now towering over the two boys, but even with their small stature, neither of them appeared to be frightened. Blaise was, though, and he edged away from their cauldron until he bumped into Theo, who was his partner.

"No, sir," said Draco, his eyes wide and innocent. "But weren't salamanders bigger back then?"

That got a laugh from the rest of the class. Snape's lip curled.

"I happen to know that you have just placed exactly nine salamander eggs in your potion, and it is precisely the color and consistency necessary for this stage," he said. "I can only infer, therefore, that you are being deliberately incorrigible by asking these incessant questions."

"We could put in another egg," Harry offered. He was not quite as good as Draco at keeping his face innocent, Blaise noticed, as the ghost of a self-satisfied smirk lingered on his face.

"You will not, Mr. Black," Snape growled, but Harry had already plucked an egg from Blaise's plate – he and Theo hadn't gotten to the salamander eggs yet when the Blacks started interrupting class – and without further ado, the Gryffindor plopped it into his cauldron. The potion's reaction was instantaneous: it began to froth and bubble and turned an odd shade of pink.

"Congratulations, Mr. Black," said Snape. "You have just earned yourself both a zero and a detention. You as well," he added, looking at Draco.

"For what, sir?"

"For pretending that you do not know how to make this potion properly," said Snape testily. "Now get back to work. Perhaps you can salvage the mess you've made, though I doubt it." He sneered elegantly and spun around to return to his desk at the head of the room.

Draco was obviously trying to look horrified, but he didn't quite succeed. Harry had his hand over his mouth to hide what appeared to be laughter. Blaise leaned over to the brothers' cauldron. "How is it he never takes points from you two?"

"He'd have to take points from Slytherin and Gryffindor both," Draco replied, abandoning his supposed horror in favor of a smug expression. "It wouldn't serve any purpose. Besides, he's a bit biased."

This was a fair point; Snape was head of Slytherin. Blaise shook his head. "But why do you even bother? All you do is get detention."

"Maybe we want detention," Harry shot back.

"But to get it by pretending you're stupid?" Blaise pressed. "You're the best in the class at Potions! Why would you ruin it like that?"

"Because we want detention. Nothing bothers Snape faster than playing dumb," said Draco knowledgably. "We've tried other methods, but anything that isn't obvious to the whole class he just ignores. Sometimes insanity is the only alternative."

"Insanity is right," Theo murmured when Blaise returned to his own cauldron. "Though I have to admit, I like this better than them sabotaging everyone else's potions."

Blaise thought back to their first class, in which Draco had somehow managed to turn Neville Longbottom and Hermione Granger's potion purple and slimy, and shuddered. "I'm just glad we don't have them together in every class."