Disclaimer: Anything you recognise does not belong to me.

A/N: At the request of the lovely operator of Padfoot's Lines, this was written for the winner of the 100th Post Contest, inspirationfollows! Congratulations to you, dear! inspirationfollows requested a story using line 70: I will not follow Potions instructions in reverse order just to see what happens. I hope you enjoy it, dear!

Potions for Dummies

Thump. Thump. Thump.

"Sirius, what are you doing?" asked Remus, gazing at Sirius from the corner of his eye.

Thump. "I'm bored, so I figured I'd rock," Sirius answered lazily. Thump. Thump.

Sirius heard Remus inhale a breath of air for patience. He knew this because that's what Remus did when Sirius was being particularly aggravating. From what Sirius could see, however, he didn't think he was being all that annoying. He was simply amusing himself. What was wrong with that?

"Those aren't rocking chairs, Pads," Remus stated calmly. Thump.

Sirius shrugged. "Doesn't stop them from working like one," he said in a bored tone, rocking his chair off the ground before letting it fall back down. Thump. "'Sides, what else am I supposed to do?"

"Oh, I don't know," Remus huffed. "You could possibly listen to the lesson. Slughorn already looks as though he's about to murder you."

Thump. Sirius snarled his nose up in distaste. "I tried that already," he replied. "Didn't do much for me in all honesty. This is working loads better."

Remus rolled his eyes and shook his head, giving up for the time being. Quicker than normal, Sirius thought smugly. I must be getting better at this.

Thump. Thump. Thump. Thump.

"Oh, for the love of bloody Merlin, would you stop?" James suddenly shouted. "You're distracting Evans from me."

Sirius snorted. "Because that's so hard to do," he muttered sarcastically. Thump. James glared at him.

"They are right, you know," Peter spoke up from beside James, twirling his quill between his fingers. "That is annoying." Sirius stared at his friend with a straight face, eyebrows raised. Peter swallowed after a moment and turned back to the parchment lying on the table in front of him.

Sirius smirked. Thump. Thump. Thump. Thump. Thump. ScriiittCRASH! "Ow! Bloody hell, Moony! What'd you do that for?" Sirius asked as he rubbed his head from where it had hit the stone floor after his chair had toppled over backwards. Had Remus really just pushed him? He looked up over his legs that were still dangling over his chair to see Remus staring down at him with an innocent face, but his eyes twinkling with mischief.

"I don't know what you're talking about," Remus said lightly. "I'm sorry you fell, Sirius, but maybe you shouldn't have been rocking in your chair." He raised his eyebrows challengingly and Sirius scowled as he flopped back against the floor.

"Mr. Black, my dear boy," Slughorn called as he finally waddled up, his bulbous stomach leading his way, "are you quite all right?"

Sirius sighed and closed his eyes. "Yes, sir," he answered wearily.

"Good. Very good," Slughorn said. "Well, then, come on, up you go and let's all return to our lesson. There's a lad, and keep all four legs on the floor this time, hm?" Sirius rolled his eyes as their professor slowly worked his way back to the front. "Now, class, turn your books to page 427 and gather your ingredients. You'll be making a Fire Protection Potion today!"

Peter turned wary eyes on his friends. "You don't think he'll actually test us on how well our potions work, do you?" he asked quietly.

"Of course not, Pete," Remus replied gently. "What type of professor would put his students in danger like that?"

"I dunno…" Sirius hedged. "He was a Slytherin, don't forget." Remus frowned at him as Peter whimpered, but Sirius saw James glance up from the corner of his eye.

"He's got a point, you know," James agreed. "Slughorn was a Slytherin, regardless of what he's like now. Something's still got to be left from that."

Remus hung his head in surrender as Peter shrank further into his seat. Sirius huffed. "Oh, relax, Wormtail," he snapped. "Prongs and I are just having you on. Slughorn isn't going to set you on fire."

Peter glanced up from under his lashes. "Really?"

James grinned and slapped Peter on the back. "Really, Pete." His grin suddenly turned wicked. "He might only try to singe you a bit." Peter squeaked and Sirius barked out a laugh.

"James!" Remus shouted in exasperation.

"What?" James said, eyes wide and innocent. Remus sighed and shook his head as he turned back to his Potions book, ignoring his friends.

Sirius snorted as James winked at him. He turned to his own book and flipped the pages slowly until he came to the correct potion and his nose twisted in distaste. Boring, his mind told him indifferently. Sirius exhaled an agitated breath of air, blowing his hair off his forehead as he contemplated what he could do to make this entire thing more interesting. His eyes skimmed the instructions and a note of caution suddenly caught his sight.

Do not, under any circumstances, perform these two previous steps in reverse order. The outcome will be most undesirable.

Sirius' lips quirked up into a large grin as a thought crossed his mind. I wonder if anyone's ever tried to brew a potion by following the directions in reverse? Probably, he concluded to himself. But never anyone named Sirius Black. With that thought in mind, Sirius raced to the supply cupboard to gather the necessary ingredients.

"What are you up to?" Remus asked suspiciously when Sirius returned, arms loaded with clinking glass vials and awkward boxes.

"Don't know what you're talking about, Moony," Sirius replied, placing his things neatly around his cauldron.

Remus' eyes narrowed as he studied the supplies. "I've never seen you this excited to brew a potion."

Sirius' arm swept his half of the table grandly. "Come now, Remus. Do you see anything here that's out of place?"

"As though that means anything to me," Remus huffed, turning back to his own cauldron.

Sirius smirked to himself. This was going to be brilliant!

Sirius' eyes went to the bottom of the page and read the last step.

Add two drops of Flobberworm mucus.

Sirius shrugged and began excitedly, continuing up the list of directions. Luckily for him, Remus was horrible at Potions, so the other boy was too focused on his own monstrosity to pay any mind to Sirius', which was beginning to emit yellow puffs of smoke. Any other time, Sirius would have viewed this as a horrible sign. This time, however, he considered it a success.

Two pinches of hellebore, three stirs anti-clockwise (so stir clockwise, Sirius' brain interjected), three measures of belladonna, and one dried Billywig sting later, Sirius' potion was finished. He examined it closely, ignoring the faint foul odour that traveled up his nose in the steam. It was a horribly lovely pale green colour and Sirius quickly spooned some into a vial and vanished the remains before Remus could see that it was not the dark blue shade it was supposed to be. Sirius sat back in his chair, propping his feet up on the table in front of him and congratulated himself on a job well done, thanking all the stars in the sky that his concoction had not blown up.

A short time later, Slughorn stood from behind his desk and called, "Time's up, everyone. Please spoon a dose into your vials and begin to clear your work spaces."

Sirius watched in amusement as his classmates manoeuvred around one another, attempting to do as they were told before class ended. As Remus finished up and came back to sit beside Sirius, his brown eyes studied Sirius curiously.

"What?" Sirius asked casually.

Remus' brow furrowed. "You finished rather quickly," he stated. "What's more is that you didn't cause any problems while doing it." His eyes narrowed again. "What are you up to?"

Sirius blew out a breath of air indignantly. "Why do I always have to be doing something? Who says I wasn't just concentrating on not blowing something up for once?"

"Because it's you," Remus replied simply.

Sirius opened his mouth to object, but James and Peter were suddenly at his side. "Come on, Pads, what are you planning?" James asked conspiratorially. "You were too quiet during lesson. I know you've got something."

Peter nodded. "Yeah, we want in," he agreed.

Remus smirked at Sirius smugly and Sirius was forced to concede the point. He began to try and explain exactly what he had done, but Slughorn was suddenly speaking again, so he was forced to close his mouth once more.

"Now, we've got about two minutes of class left, so what I want everyone to do is trade their vials with their partners," he instructed. "Let's test out how well you did."

Sirius froze as everyone began to reach for their potions. He hadn't expected that. Not at all. He gazed at the vial of green liquid in his hand and swallowed. Remus was going to kill him.

"All right, Padfoot, let's see it," Remus said as he waved his vial of blue potion in front of Sirius' face.

As Sirius handed over his own potion, he grabbed Remus' quickly, uncorked it, and swallowed it all in one go. He suddenly felt cold; as though he'd been covered in a layer of thick ice and he assumed that his friend's potion had been successful. He chanced a glance at Remus and saw the other boy studying the green liquid doubtfully. His eyes turned to meet Sirius'.

"What did you do?" he asked warily.

"Erm…" Sirius said intelligently.

"Mr. Lupin, is there a reason you have yet to try Mr. Black's potion?" Slughorn said as he waddled up.

"Er…well, Professor, you see…" Remus attempted before trailing off and holding the vial up to eye level for Slughorn.

Slughorn shook his head. "Come now, boy!" he exclaimed. "Are you Gryffindor or not? Mr. Black is a marvelous Potions brewer. I'm sure whatever that vial contains will be remarkable!"

"Sir, I really don't think –" Sirius began, but cut himself off when Remus uncorked the small bottle and swallowed the liquid inside.

Sirius watched with bated breath as he waited for something to happen. He didn't have to wait long, however, as Remus' skin suddenly turned a bright purple hue. Sirius' mouth gaped open, almost in relief, as nothing else happened.

Remus raised his arms to study his skin. "Well, I suppose if that's the worst it – ARGH!" He screamed as his hands suddenly vanished before his eyes and a lead weight dropped into the pit of Sirius' stomach. "You bloody mutt! Where the hell have my hands gone?"

Sirius' eyes darted around the room. "Erm…Have you checked your pockets?" he asked weakly with an uneasy smile. Remus scowled and glared at him angrily and Sirius took a few steps back, just to be safe. Even a hand-less Remus Lupin was a danger to Sirius' (rather impressive, if he may say so) manhood. "Calm down, Moony. I'm sure we can fix this."

"What if we just fix you instead?" Remus growled as he advanced and Sirius' hands quickly moved to cover his threatened manhood. "I think that sounds like a perfect –"

Sirius watched in awe as Remus' feet began to swell like balloons and the boy slowly turned upside down and floated to the ceiling. James gawped at Sirius.

"What the hell did you make?" he asked in amazement.

"Er…" Sirius said, his eyes following Remus' ascent. "Sorry, mate!"

He turned on his heel, darting to the door as quickly as he could, Remus' shouts trailing behind him as he raced from the dungeon room.

"Black, you berk, come back here and help me down or so help me, I'll bloody well murder you in your sleep with your dirty socks!"