Sirius threw his hands up in exasperation. "Bloody hell, I can't do it James!"

James rolled his eyes. He was sat cross-legged on his bed, flicking through a copy of PlayWizard, whilst Peter lay sprawled on the adjacent bed, already tucking into his second box of Bertie Bott's Every Flavour Beans. "McGonagall said it was the most basic switching spell in transfiguration, and you're pretty good at spells, Sirius. You're just not concentrating properly."

Sirius huffed. "Easy for you to say, you got the spell right third try. You know me, Jamie, I get bored faster than you can say 'Quidditch'. I'm just so sick of practicing this bloody spell. Merlin's pants, even Peter's managed to do it. It can't need that much concentration. No offence, Peter."

"None taken." Peter replied, popping a sausage flavoured bean into his mouth. It was pretty much common knowledge that Peter sucked at spells, so it didn't really bother him that much, and to be honest, it was pretty amusing seeing Sirius struggling with his magic when he was so used to doing it with ease.

Sirius sighed, then regained his composure. This was it. He was going to do it this time, and if not, well then, transfiguration could go suck his…well, yes…All he had to do was focus on turning the mirror next to the door into a coat rack. Easy peasy. He stood up straight, rolled his shoulders back, and took a proper stance. Taking a deep breath, he fixated his eyes on his target as his eyebrows furrowed in concentration. "PERMUTOS!" he yelled with all the energy he could muster, and flicked his wand.

But just at that moment, the door swung open, revealing the small form of Remus Lupin, carrying what seemed to be a tower of textbooks in his scrawny little arms. The spell hit him directly in his stomach, sending the two boys sprawling. A harsh bright light began to emanate from their bodies, causing James and Peter to shield their eyes. As the glow dissipated, James and Peter gave each other a worried glance, before looking back at their two friends' bodies lying motionless on the floor.

"Sirius…? Remus…?" James croaked.

"Bloody hell!'' Remus said, blinking his eyes open. He rubbed his temples, wincing slightly at his pounding headache as he pulled himself up off the floor.

James and Peter's raised their eyebrows so high, that they almost touched their hairlines. Remus… swearing? Well, that was new! They then turned their attention to Sirius, who was also coming around.

"What? What happened? Where are my books?" Sirius mumbled, as he climbed up off the hard floor.

Remus yelped. "What…what am I doing over there?! How…?" he garbled, not sure of how to express himself. What in Merlin's name was going on? Why could he see his own body on the other side of the room?

Sirius looked so terrified, James could have sworn his hair almost stood up on end. "That's…that's me. What's happening? You don't think…we haven't…no we couldn't possibly…" he trailed off, running over to the mirror.

Remus followed, desperately wanting to see his reflection. They both inhaled sharply, just as James and Peter burst into fits of hysterical laughter.

"WHAT HAVE YOU DONE?!" Remus, in Sirius' body, cried.

"What have I done? What have you done? Why did you get in the way of my spell?" Sirius, in Remus' body, retorted.

"How was I supposed to know you were doing a spell! I had just come back from the library!"

Sirius' lips twitched slightly into a smile as he glanced over to James who was almost in tears from laughing.

"Are you smiling? Do you find this funny? Well, it's not! Turn me back right this instant." Remus barked back hysterically, his voice several octaves higher than usual.

"I don't know how. I don't even know how I made us switch places in the first place! Lighten up, Moony."

Remus narrowed his eyes, and much to his displeasure, Sirius smirked. That was the last straw. He leapt onto Sirius, causing them both to fall backwards into a heap as they began wrestling with each other on the floor.

"It's all…your…stupid…fault!" Remus gasped.

"It's all your stupid fault." Sirius mocked in a girly voice.

"Why can't you be serious for once, this isn't funny!"

"I am serious. My name's Sirius."

"Oh, hilarious." Remus retorted sarcastically.

"Okay, okay. Break it up, you two." James commanded, still chucking slightly to himself as he separated the two boys who were flailing their limbs at each other.

Remus glared at Sirius furiously. He was always getting him into trouble.

"So, you've switched bodies." James stated bluntly.

"Well, thank you, captain obvious." Sirius quipped.

"So, we can either take you both to Madam Pomfrey…"

"NO!" Remus and Sirius yelped. Another week's worth of detention was the last thing they needed.

"Or…we'll have to try and find a counter-spell ourselves."

"That could take weeks." Remus whined, with a pained expression on his face.

"What are you so worried about? At least now you've got my ripped abs and perfectly chiselled jaw. Instead, I'm stuck with your ugly mug." Sirius teased as he pulled a face, earning him a glare from Remus.

"You think I'm going to enjoy living with your feminine locks?" he huffed, trying to blow the long black strands of hair out of his eyes.

"You wish you had my feminine locks. Consider yourself lucky, I've just shrunk about a foot! I'm the one who seems to have got the shit end of the stick here."

"It's perfectly normal not to have had my growth spurt yet! And in any case, I'm not short."

"Last time I checked, just over 4 foot was pretty short…"

"Alright, alright. Can you stop biting each other's heads off for just one second? We need to find a way to fix this before somebody finds out. Tomorrow we'll go to the library, and see what we can do."