Gift Exchange for jawncakes . tumblr .com, for the johnlockchallenges gift exchange.

Based on their prompt: Pranks, Ravenclaw!Sherlock, Gryffindor!John

A/N: Well, this was a really fun piece to write, and I'd love to write more in this verse. Thanks jawncakes for making me come up with this! I'm not sure if I'll write more, but I definitely have some ideas, so stay tuned!

John really wasn't sure why he was the one who was doing the research in the library for the prank war the third year Gryffindors had going on between the Hufflepuffs. His roommate Percy was much better at the whole research thing. John was more into the actual pulling off of the pranks. He preferred the rush of adrenaline that came from a close call much more to the supposed rush from finding the right book, or information. Or at least, that's what Percy said happened.

He was trying to find a book about colour-changing spells – the latest idea for the Gryffindors – when he heard them. Hiding behind a bookshelf, John eavesdropped on the conversation. The quieter, female voice seemed to be taking instructions from the bossy, male voice. John closed his eyes as he realized who exactly it was that was talking. Sherlock Holmes.

Sherlock Holmes was 3 years younger than John but was in the same year, and while he had seemed alright when John had met him on the train back in first year, John had quickly learnt that Sherlock was standoffish, rude, cold, unfeeling, and downright mean sometimes. John knew some about the boy, but had spent as much of his school career avoiding the Ravenclaw as possible, which wasn't the easiest this year what with sharing all his extra courses with the boy. Especially after that incident on the train in second year-

John shifted again, pulling himself from his memories, and trying to focus on the voice of the dark haired boy talking behind the bookshelf. However, the boy stopped just as John started listening again, and John froze.

"You do realize we can see you back there. Come on out," the posh accent of the Ravenclaw was heard and John wanted to smash his head against the bookshelf.

"Alright Watson, keep yourself together, you're a Gryffindor, you can do this," John thought to himself before turning into the next isle, seeing Sherlock Holmes, as he had thought, and a Hufflepuff John was pretty sure was in his year – Maggie? Maddy? Molly? Molly, that was it!

"John Watson."

"Sherlock, Molly."

Molly blushed, and stammered. Sherlock looked away from John for a second to stare at the brunette, before turning back to his new prey.

"Was there any particular reason you were spying on us, Mr. Watson?" Sherlock asked, doing an incredible imitation of McGonagall.

"I was just looking for a book." John shrugged his shoulders in a way that he hoped looked relatively innocent. "I wasn't trying to spy, or listen in or anything, you just happened to be talking relatively loudly."

Sherlock narrowed his eyes. "Army or Navy?"

John stared at him. "I'm sorry?"

"Your father. Was he in the army or the navy?"

"Uh… Army. How- how did you know?"

"November 11th. For the past 3 years you wear a poppy for that day, and you wear it again on the 29th of January. I looked up any famous battles that happened on that day, but you have to go back almost 300 years, and you aren't the type to wear a poppy for a great-great-great-grandfather, or whatever. You also almost snap every January, and while your dorm mates don't know, they are always more careful with you around those days. Your poppy is always worn with a sense of pride and held with a specific-expensive- pin, but your clothes are second hand, as are your books. You also hold yourself in a distinctly militarial way. It's obvious, father was in the military and died," Sherlock said, almost bored, but his eyes gleamed in a way that took away from his tone.

"Amazing. But, yes, true. My father died in Ireland a few years before I came to Hogwarts. I don't like to talk about it." Molly smiled at him sadly.

"I understand, my mother died in the war against You-Know-Who when I was two." John looked at her, she seemed different now that he knew something about her – other than her name and house. But then, he supposed, that was always the way it was with people. The more you know about them, the more they become people.

"Anyway, it's nearing curfew, I need to go," John said, quickly, trying to get out of the awkward silence that had fallen on the group of three after Molly's statement.

"Not so fast Gryffindor. I need your word that you won't breathe a word of this new plan to anyone," Sherlock cut in, stopping him in his tracks.

"I don't know how you're going to insure that, but I didn't hear anything, so I'm not sure how that could help anyone," John said, really just wanting to leave the strange boy who knew too much and the girl who he couldn't help but pity.

"Oh, I have an idea," Sherlock said, rubbing his hands.

"I'm not sure if I like this plan…" Molly whispered to the two boys as they hid in a closet, waiting for Filch to pass.

"Relax Molly," Sherlock said, giving the first real smile John had ever seen him give. "It's not as though we're going to get caught."

"I'm with Molly on this one, it seems a little dangerous, and very ambitious for three third years." Sherlock turned towards John, his big grey eyes going almost puppy-like, his lip almost pouting at him. John felt his resolve start to squirm. Obviously Molly did too, because the next thing he heard from her was "Alright, nevermind, I trust you Sherlock."

Sherlock rubbed his hands together, but John still wasn't convinced. "Remind me again why we're doing this to all the houses?"

Sherlock rolled his eyes at the question, before slowly opening the door and leading them towards the dungeons. "Because then the teachers will have no idea where to start looking. You're going to have to "fall" for it too. I'll enjoy seeing you tomorrow with blue hair, Molly," he teased the smaller girl walking towards an empty wall.

"Uh, Sherlock. It may seem a little late, but how exactly are we going to get into Slytherin common room?" John asked.

"My brother always gives me the password- or I guess it. They're not exactly the hardest things to guess. Even the Gryffindors choose better words. Newt-eye."

The wall slid across to open to an empty, dimly lit room with couches everywhere. Sherlock slipped in, with John and Molly behind him, and zipped into what John thought were probably the dorm bathrooms, and slipped out a few minutes later. It wasn't until they were out in the hall again that John felt safe enough to breathe. If anyone had come… John would have been dead meat. The other two weren't the rival house to Slytherin, and so they probably would have survived. But- anyway, it didn't matter. They did it, no one came, everything was good. The prank was set for tomorrow morning.

The next morning was pandemonium. John didn't know how it had happened, but he was sort of enjoying the look of panic on everyone's faces when at breakfast everyone's hair had changed colours. The Hufflepuffs had bright red or gold hair – obviously Sherlock had decided to be nice to Molly after she almost fainted the first time he had thrown the idea of her having blue hair. The Ravenclaws were trying to unspell their green or silver hair, unsuccessfully. The Slytherins looked like they wanted to kill whoever was responsible for turning their hair yellow or black – except for the seventh year John identified as Sherlock's brother, who was simply looking for his brother at the Ravenclaw table. John was doing the same, but as of yet, Sherlock had yet to arrive at breakfast. John brushed his bright blue hair out of his face as he dug into his eggs, content in the information that no, Sherlock was not coming to breakfast, and tried to ignore Percy who was freaking out about his hair.

Suddenly, explosions went off, and John's training kicked in, pulling his head in tight, and slipping off the bench, he opened his eyes enough to see the first set of fireworks go off, leaving ribbons in their wake that twisted into the words "Courtesy of the Lion, Eagle, Badger, Snake". John had to chuckle, after he sat back up. Looking to the doors, where he could just see a dark figure, John lifted his glass to the Sherlock Holmes, and smiled.

THE END