I wrote this for Nuhuh on DLP when I accidentally wished him a happy birthday and hit 4000 posts. I'd been saving my 4000th post for a story, so I had to go back and write one to edit it in or regret it for the rest of my days.

Fred dropped a single leaf of worrywart into the bronze cauldron and lifted the stirrer, watching. The instant it dipped beneath the black liquid, he cast incendio at the base and began stirring in long, clockwise strokes.

One, two, three, four… "Now," he said. George tilted open his paper and exactly three point four grams of primrose, steeped in frog entrails for two hours, poured into the cauldron. Neon orange followed the swirling ingredients as Fred continued stirring in an even pattern.

The moment color replaced the black, George cleared his throat and leaned over, his nose an inch from the potion. "Nuhuh," he said, dipping in the tip of his wand, and the potion turned clear.

They stared, not breathing, for the requisite five seconds in which potions tended to explode if they were so inclined. Then the twins relaxed, sharing an identical grin.

"Think it'll work?" asked Fred. He laid the stirrer on the table and started ladling portions of their creation into jars.

"Should," said George, reaching over to help. "Not much different than the one we tested on Abercrombie."

Fred nodded and tightened the cap on the last container. "In that case, it is our solemn duty to teach McGonagall the beauty of the word 'nuhuh' once and for all."

"A marvelous statement that imply either an affirmative or a negative, all dependent upon ones inflection! I can't believe she lectured us for saying it."

Fred held a jar up to the light in triumph. "Well, after today everyone will appreciate the grandeur of 'nuhuh'."

George laughed and waved his wand, cleaning up the mess in the remote classroom. Fred followed with a spell that sent their orderly workshop into disarray-twisting chairs to odd angles, tilting the torches on the wall, and half pooling the curtains on windowsills. George finished up with a simple dust conjuration before they left for the Great Hall. Wouldn't do for anyone to notice the room being used, and a good prankster took care with his lair.

"Staff table too, you think?" asked George.

"Yeah," said Fred. "Each drop should probably be at least the size of a knut, but I can spread them out to get everyone. How long to cast your charm?"

"Five minutes."

It took them six and a half, but no one stumbled upon their machinations at four in the morning. A sleepy-eyed First Year, bribed last night with half a dozen canary creams, opened the portrait hole for them at precisely four thirty. They shuffled off to bed.

Breakfast started at six thirty each morning. Fred and George showed up a few minutes after, finding a crowd of early risers clustered several feet away from the door.

"What's going on?" Fred asked. George eyed the surrounding crowd, noting representatives from each house. Plenty of witnesses.

"The door shoots water at anyone who gets too close," said a tiny Ravenclaw boy, laughing. He stepped forward, grinning, and got a gout of water to the face.

Fred laughed with him. "Have you tried shooting back?"

The boy, likely a muggleborn first year to be so excited over an inconvenience, didn't respond except to grin once more and get out his wand. "How?"

Fred returned the smile and waved his wand, drying him off. It was chilly, and if they got caught he did not want McGonagall after him for giving the firstie a cold. "What's your name?"

"Danny!"

"Here," said George, walking up to crouch down beside the kid. "Watch me, the wand movements are simple. Aguamenti!" A brief stream of water flew out of his wand and splashed against the door. The charm flickered yellow, then fired back. George deflected the watery assault towards the rest of the group and it hit Hampsen, one of the Slytherin beaters, square in the face.

He growled. "It's too early for your bullshit Weasley!" He cast the drying charm on his damp robes, pure velvet from the looks of them, and took a menacing step forward. "Did you jinx the damn door?"

"What, just because we've heard of the charm means we're guilty? We just got here!" said Fred. He opened his mouth to say something else, but stopped. "Nevermind, let's just break it so we can eat."

The larger boy eyed them with suspicion, but turned and cast the charm as well. Soon everyone joined in; the older students who could cast a shield stayed dry, but the younger years took splashes from every side. Fred stood back and made a show of vanishing the expended water.

"Aquamenti!" shouted the little Ravenclaw, wilting when it didn't work.

"It's 'aguamenti,' with a 'g,'" corrected George, "and less of a flick at the end, you want a steady hand. Aguamenti!"

Twenty seconds of dedicated assault later, the charm erupted in a flash of blinding light just as Fred sent a gust of wind towards the doors. It blew them open with a bang, scattering torrents of water throughout the Great Hall.

"Great fucking timing, Weasley," said Hampsen. "Now the damned tables are wet." He strode inside with an angry gait and headed towards the Slytherin side just as dishes began to appear. The house elves didn't send them up until the students arrived each morning.

Fred and George checked that the younger years dried off, then grinned and draped their arms around one another's shoulders. "Perfect, brother mine," whispered George.

"Indeed," said Fred. They sat at the Gryffindor table and filled their plates with kippers and bacon, careful to avoid the large droplets of clear liquid strewn about the table. "Even I can't tell which is which."

They ate slowly, watching as the rest of the staff and student body arrived over the next hour. A handful bothered to ask about the mysterious liquid scattered throughout the room, but when they did another student was quick to explain that it was 'just water' leftover from a prank that morning.

Dumbledore or Snape might recognize parts of it as a potion, but the Headmaster never told and Snape took breakfast in his quarters most mornings.

Time to test it. George pinched off part of his biscuit and flicked it across the table towards Percy's juice. He missed. Tried again and made it. Percy didn't notice, but Fred joined in the fun and it didn't take long.

"What do you want?" Percy asked, slamming his glass on the table after drinking a chunk of soggy biscuit. "Must you continue to act so childish? As Head Boy I demand you cease or I will deduct points. Yes-" he paused here, as if he'd expected someone to interrupt him, but no one did, "-even from my own brothers."

Perfect. "I dunno Perce, must we act so childish? Come on now, yes or no."

Percy glared and took a deep breath, puffing himself up even as the tips of his ears turned red from anger. "Nuhuh!" he said.

His bug-eyed look at what came out of his mouth was fantastic. George looked around for Creevey, but he was on the other end of the table trying to sneak pictures of Harry again. He caught Fred's eye and worked to stifle his grin. They still had to test the trickiest part.

"What's that Perce?" asked Fred. "Got something stuck in your throat?"

"Nuhuh!" Percy said, this time changing his inflection on the last syllable so that the tone of his voice went down, indicating a negative. Or "no." When he answered the earlier question his voice had gone higher, for "yes."

Percy scolded them for 'whatever they'd done this time' in the background, but Fred ignored him. It worked. He made a fist and met his brother's identical one under the table in triumph. Anyone who touched the potion he had sprinkled over the breakfast tables last night would answer with "nuhuh" for yes or no questions. Pronunciation alone able to provide clarification of their answer.

And it was Friday, so McGonagall would give her patented yes/no quizzes in classes today. She'd ask random students yes or no questions and assign points based on their answers, but today she'd get nothing but 'nuhuh.'

Victory was sweet.

McGonagall stalked towards them from the Professor's table. They frowned. It was too early for her to suspect them. She would eventually, of course, but any remaining proof should be long gone by then. They busied themselves making cups of tea, hoping she was on the warpath with Harry again instead, but no such luck.

She stopped just behind them, the front of her robes brushing against their backs. "What's this I hear about the doors to the Great Hall shooting water at first years this morning?"

George slurped at his tea to buy time but succeeded in burning his tongue. Fred answered for him. "Professor McGonagall! You look absolutely ravishing today."

"I am standing behind you, Mr. Weasley." George could hear the smile in her voice. "Now, the door?" Good humor fled her voice and she put one hand on each of their shoulders. But it took more than a threatening Professor in their personal space to deter either of them.

George crossed his fingers and spoke. "Come on Professor, yes or no. I'm not admitting we did it, but wouldn't a prank like that be just a little bit funny?"

"Nuhuh," she said. For a second her hands loosed on their shoulders, showcasing her surprise, and everyone in Great Hall within hearing distance silenced in shock.

McGonagall simply did not say things like 'nuhuh.'

A second later her nails dug back into their shoulders with surprising force and she jerked them around in their seats. If Fred didn't know better he'd think she growled.

"Well, guess the cat's out of the bag," he said. George snickered as McGonagall's eyes narrowed and nostrils flared.

"What do you guys think," Fred called out to the Hall. "Worth it?"

"Nuhuh!" everyone chorused.