Disclaimer: Harry Potter belongs to the fabulous J.K. Rowling and Sherlock belongs to Moffat, Gatiss, and Conan Doyle.

I never thought I would write a crossover, but this idea hit me and I couldn't shake it off. I have not seen any fanfictions or fanart where John and Sherlock are in the same house, so I put them both in Ravenclaw. Many thanks to my friend SK for her feedback and encouragement. Also, John and Sherlock's wandwoods reflect facets of their characters. If you are interested, check out the list of wandwoods and cores that was originally posted on Pottermore. Happy reading!

"No, John."

"I haven't even asked you anything yet."

"You're going to ask me to come to your Quidditch match tomorrow, even though you know I abhor the sport and am extremely preoccupied with this analysis of poison potencies."

John snapped his mouth shut angrily when he realized it was hanging open. He sometimes wished Sherlock were skilled at occulemency, rather than just being the annoyingly-observant git he was almost 100% of the time.

"Please come, Sherlock."

"The addition of the world please does not make me any more inclined to attend," Sherlock stated as he added lavender to the infusion of wormwood and snake fangs brewing in his cauldron. A puff of blue smoke wafted slowly up from the mixture as he reviewed a sheet of paper covered with his messy scribble.

"It's a big match, Sherlock. We're facing Hufflepuff, and they're undefeated this season."

"Still not interested," Sherlock replied under his breath, though he knew John would hear him.

"It's our sixth year, and I'm captain of the team. In the all the time we've known each other, you've never come to a single match."

Sherlock placed his wand (sycamore and dragon heartstring, 33 centimeters) on the table and spun in his chair to face John for the first time.

"Why is it so important that I come?"

"Because you're my friend! And friends support each other, even if they don't enjoy the same things. I would like you to be there, Sherlock. Is that really too much to ask?" John shouted. Sherlock stared at John for a moment, then turned back to his cauldron.

"I'm too busy."

John let out a growl of frustration, walked around to the other side of the table, and placed his hands on top of Sherlock's notes, forcing his friend to look at him.

"I have a busy life too. My medical tests are at the end of this year and I'm taking extra classes for Healers, yet I still find time to help you solve cases. I blew Sarah off on Valentine's Day last year to figure out who was sending anonymous Howlers. We also missed the Halloween feast so you could figure out who had stolen Hagrid's pumpkins, only to find out the Thestrals had eaten them. And to top it all off, I spent all of Christmas day, after you convinced me to stay at school over break to keep you company, hunting down the extensive Weasley family's stolen sweaters. I think you owe me one lousy Quidditch match."

"The answer is still no, John."

John emitted a strangled sigh, but then a resigned look came over his face and his shoulders drooped. He ran a hand through his hair.

"Fine. Don't even know why I bother. Sorry for wasting your time." Sherlock didn't respond; he just kept adding newt tails to his potion. John looked down at his friend for a moment and then headed toward the boy's dormitories. At the foot of the stairs, John glanced back at Sherlock once more and then trudged up the stairs.

Sherlock steepled his fingers under his chin and stared off into the darkness of the empty common room. The silence didn't last long. Molly came down from the girl's dormitory a moment later, sporting a pair of cat pajama bottoms and a Puddlemere United t-shirt. Sherlock barely managed to smother a groan. Molly was in her fourth year and had an annoying tendency of turning up at the worst moments. The Hoopers were family friends of the Holmeses, so Sherlock tolerated her presence, to an extent.

Molly timidly approached Sherlock. "I couldn't help but overhear your and John's conversation," she started.

I'm sure you couldn't, he thought to himself.

Molly sat down at the table across from him. "Sherlock…well…um…you weren't being very nice," she blurted.

"I'm never nice," Sherlock responded, frowning at the watery consistency of the potion that was supposed to be custard-like at this point.

"Well, meaner than usual," Molly countered, giggling nervously. "Why won't you go to the match tomorrow?" Sherlock sighed dramatically.

"As I told John, I don't enjoy Quidditch and I am busy," he explained through clenched teeth.

"Do you think John enjoys the violin?" Molly asked unfazed by his tone.

"Tolerably well, why?" Sherlock replied, perplexed by the sudden change in topic.

"How many of your recitals has he gone to?"

"I've never noticed," he answered airily, suddenly realizing where this conversation was headed. Molly laughed.

"Sherlock, you are the most observant person I know, so I doubt you didn't notice. I've been to every single one, and I always see John there."

"I don't see the point of all this," Sherlock responded petulantly.

"At your last performance, John was running on three hours of sleep since you had kept him up all night solving a case. He missed dinner because of a class that ran late, and he had another full night of studying ahead of him for a Healers' Anatomy and Physiology exam the next day. Despite that, he stayed for the whole thing and didn't fall asleep once, at least not while you were playing." Sherlock stared grumpily at his cauldron. He could feel Molly's eyes on him.

"He does a lot for you, Sherlock, and all he's asking for in return is a few hours of your time. Sarah and I are heading to the pitch after lunch tomorrow. You're welcome to join us." With that said, Molly got up from the chair and walked back upstairs.

Sherlock cast one final disgusted look at his potion and then waved his wand over the mixture, causing it to disappear into thin air. He groaned inwardly then rubbed his eyes. Guilt was such a pointless emotion, a complete and utter waste of time and energy. Despite this, Sherlock could not deny the nature of the feeling that had crept up on him during his conversation with Molly. Sweet, quiet little Molly who had somehow found enough guts to lecture him on his behavior. What was the world coming to? Sherlock angrily picked up his cauldron and headed up to the boy's dormitory. Sometimes he hated having friends.

The next afternoon, Sherlock reluctantly found himself bedecked in Ravenclaw's colors and sitting in the bleachers of the Quidditch pitch. Molly sat on his right, talking animatedly with Sarah and several of her friends. John's girlfriend, though in Gryffindor, had borrowed one of Molly's scarves and bewitched her hair to change from blue to bronze and then back again. Now she was doing the same to Molly's locks.

"Want me to do yours too, Sherlock?" Sarah asked, waving her wand threateningly. Sherlock shot her a forced smile. John was always telling him to smile more, something about it making him look less like a serial killer.

"I'll pass."

Sarah shrugged and went back to talking to Molly. Sherlock stared morosely at the field and thought longingly of his cauldron sitting empty in the dormitory. What was he doing here?

The Ravenclaw crowd stood as one as Lee Jordan's voice echoed throughout the stadium. Molly pulled Sherlock into a standing position as well. Lee announced the Hufflepuff line-up and then Ravenclaw's team.

"And for Ravenclaw, Chasers Sally Donovan and Roberto Argenian, Keeper Mitchell Vesper, Beaters Veronica Rowley and Charles Eppley, Seeker Patricia Neals, and team captain, John Watson!"

Molly and Sarah let out ear-splitting cheers as John flew onto the field. Sherlock managed a genuine smile and a small clap. That title suited John.

After a few laps around the circumference of the pitch, John alighted on the ground. He shook hands with Hufflepuff's captain—a stocky fifth-year by the name of Dimmock—then both boys took off into the sky to join their teams. Madame Hooch blew her whistle, and the game began.

"Donovan takes possession of the Quaffle, dodges a Bludger hit by Oakston, now she's gaining altitude trying to break free of Hufflepuff's Chasers, but no, she passes to Watson in a perfect Porksoff Play! Watson heads toward the goal posts—he shoots, he scores! 10-0 Ravenclaw!"

The blue-clad Ravenclaw supporters leapt out of their seats, drowning out Lee's commentary and leaving Sherlock looking up in confusion at the fanaticism of his housemates.

"Argenian scores on a reverse pass from Donovan. Hufflepuff takes possession and Markleby scores by faking out Vesper. Dimmock intercepts a pass from Argenian to Watson and scores again for Hufflepuff, tying up the match at 20-20. Argenian has possession once again; he's flying toward the hoops—and oh! That couldn't have been clean. And it's not. Madame Hooch calls a foul on Rowley for excessive force."

The Ravenclaw supporters began to boo. "What are they complaining for?" Sherlock asked. "It was a flagrant foul." Sarah shot him a look of disbelief.

"Nobody cheers when their team commits a foul. We don't like to admit that we were in the wrong, a sentiment I am sure you can relate to," Sarah replied cheekily. Sherlock shot her an angry glare. "Besides, when do you know anything about Quidditch?" Sherlock pulled a copy of Quidditch Through the Ages from his robes.

"That's John's," Sarah observed, though she was really not surprised. Sherlock did not seem to comprehend the concept of ownership.

"I borrowed it from him last night."

"More like stole it, seeing as you two weren't on speaking terms last night," Molly remarked quietly. Sherlock scowled at her, while Sarah laughed. Sherlock reluctantly turned his attention back to the match.

"And Calven takes the foul shot for Hufflepuff and earns another 10 points for the Badgers who take the lead. Watson has possession, breaks free of Hufflepuff's Chasers—man he's really flying on that Nimbus 1700—and he scores! Dimmock passes to Markleby, but he's intercepted by Donovan who passes to Watson, and Watson scores again! Captain Watson is on fire today!"

Sherlock managed to keep up his feigned disinterest until 20 min into the game when John executed a one-handed Sloth Grip Roll to avoid a Bludger and then score, breaking the 130-130 tie. He jumped to his feet with Molly, Sarah, and the rest of the Eagle supporters. Mid-clap, Sherlock realized Molly and Sarah were staring at him in astonishment. He gave them a small grin in return.

10 minutes later, Ravenclaw had a 40-point lead, but Salvatore—Hufflepuff's Keeper—kept blocking everything Ravenclaw's Chasers threw at her. John had just gotten possession of the Quaffle when several things happened at once.

Out of the blue, a Bludger hit by Eppley changed course midflight and barreled straight for John's head. John just barely managed to dodge the Bludger and it slammed into Vesper's chest, knocking him off his broom. John dove after his fallen teammate and Madame Hooch had just begun to blow her whistle when Lee shouted, "Neals has the Snitch! Neals has the Snitch! Ravenclaw wins, 320 to 130!"

The applause from the Ravenclaws was deafening, but it slowly began to dissipate into worried murmurs as they noticed Watson and Vesper on the ground, surrounded by several professors. Dumbledore was waving his wand over the Keeper's prone form.

After several moments, Dumbledore conjured up a stretcher and headed off toward the castle, Ravenclaw's team trailing behind him. The stands began to clear and Sarah, Molly, and Sherlock followed the crowd out of the stadium.

"Did anyone else notice that Bludger change direction and come straight at John?" Molly asked.

"Yeah, I did. Thank god John has good reflexes," Sarah remarked. "I hope Vesper is alright."

"Nobody hit that Bludger, yet it was targeted at John," Sherlock stated. Molly looked at him in horror.

"Who would want to hurt John like that?"

"I don't know, but I intend to find out."

"Look, I'm just as shaken up as the rest of you," Sarah started. "But there could be a hundred other explanations for this."

"I agree with Sherlock," Oliver Wood—the fourth-year captain of Gryffindor's team—said as he came up to join them. "Madame Hooch checks the equipment for tampering before every match, but in all my years playing Quidditch, I've never seen a Bludger act like that. Somebody wanted that Bludger to do damage."

"It still could have been an accident, or maybe a prank from some Hufflepuff student," Sarah said stubbornly.

"They would have had to spell the Bludger midflight. You have no idea how fast those things move when you're up in the air. That would take a considerable amount of skill," Wood explained.

"A feat I doubt most students are capable of performing," Sherlock added.

"Well," Sarah sniffed. "I am not going to jump to conclusions until I have more data, something you of all people should understand, Sherlock." She sped up to walk with her Gryffindor friends. Sherlock made a face at her retreating back. The three of them strode in silence into the entrance hall where Wood bid them goodbye. Molly and Sherlock headed up to the Ravenclaw common room to find Sarah waiting for them. Sherlock sat and stared at the fire, replaying the scene over and over in his mind, looking for anything he might have missed, while Sarah and Molly talked with some of the other Ravenclaws.

About an hour later, John and the rest of the team, minus Vesper, trudged into the common room. John cleared his throat and announced, "Mitchell is going to make a full recovery. He had three broken and two cracked ribs, as well as a collapsed lung. Dumbledore managed to stabilize him until we could get him to Madame Pomfrey. She worked her magic and he should be back in action by the end of the week. We'll be ready to crush Gryffindor in the next match of the season."

The Ravenclaws let out a shout of excitement, the tension in the room dissipated, and the victory party began in earnest. John smiled at the people who congratulated him on the win as he made his way to the couch. He plopped down exhaustedly between Sherlock and Sarah. Sherlock wordlessly handed him a cup of tea and several Pumpkin Pasties. John accepted them with a muttered, "Thanks."

Sherlock opened his mouth several times to barrage John with questions, but Sarah and Molly silenced him with a glance every time. John finished and looked up at his friends' expectant faces.

"He was in pretty bad shape down there," John said quietly, clenching his fists. "I was afraid he wasn't going to make it." Sarah rubbed his back and some of the tension dissolved from his shoulders as he leaned into her.

"Sherlock thinks the Bludger was meant for you," Sarah stated worriedly.

"That sounds like the freak. He has to see murderous intent in everything," Sally said as she walked up to their group. Sherlock scowled at her.

"I don't see how it could have been meant for anyone else, Sally," John replied firmly. "Mitchell and I were the only two people in that part of the pitch, and it came too close to me to have been meant for him."

"You mean to say that Bludger just decided to come zooming straight for your skull? Last thing I saw, Eppley had hit it towards Dimmock," Sally asked disbelievingly.

"That is exactly what we are suggesting, Sally, but if that is beyond your small powers of comprehension, then perhaps you should leave this to the rest of us," Sherlock said icily. Donovan moved toward him threateningly, but John held his hands up.

"That's enough you two. I know it sounds crazy, Sally, but it seems to be the case."

"Do you think someone tampered with it?" Molly asked.

"That's what the professors were saying," John said, running a hand through his hair. "They have to examine it more closely, but I don't see any other explanation."

"The question now is who would want you out of commission?" Sherlock stated. John turned to look at his friend.

"It wasn't anybody on Hufflepuff, that's for sure. The whole team looked crestfallen, and Dimmock's a decent fellow; he came into the hospital wing and apologized for a good ten minutes. I don't think they were responsible."

"What about somebody from Gryffindor?" Molly asked. "Or maybe Slytherin. They barely beat you this year. Maybe they thought you were a threat for the cup."

"Oliver may be a fanatic, but he wouldn't go so far as attempted murder to win. Flint's barely bright enough to tie his own shoes, so I doubt he could concoct a plan like this."

Sherlock let out a laugh at John's comment, which was entirely true.

"Yeah, but not all the Slytherins are that dumb," Sarah said, her eyes narrowing.

"Sarah, we all know how much you love Slytherin, so let's leave it at that," John replied kissing her cheek. Sherlock rolled his eyes at this display.

"So, we've got nothing," Sally stated.

"No," Sherlock corrected. "We know the spellcaster was skilled, he or she would have to be in order to charm a Bludger in midair. This rules out most of the younger students. The suspect is unlikely from Ravenclaw as it would be irrational to take out our own captain. Also, we know they either had to be present at the match or have an accomplice who was present at the match as the Bludgers passed Madame Hooch's pre-game inspection. And, in a few days time, we will have the nature of the spell cast on the Bludger. I would hardly call that nothing, Sally."

Sally shot him a look that clearly said, one day you'll get what's coming to you, and then walked away from the group to go talk to her Slytherin boyfriend, Anderson.

"Who let him in here?" Sherlock asked disgustedly looking over at the pair.

"Sherlock, leave it," John ordered wearily. "I am not in the mood to hear you belittle Anderson tonight." Sherlock frowned and sighed resignedly. Silence fell until John looked up to see Sarah and Molly staring at him with concerned expressions on their faces.

"Look, I'm not going to worry about this until we have more information. There's still a slim chance it was an accident. Can we please just enjoy the party?" John reasoned.

"Of course," Sarah replied, kissing John on the lips, eliciting another eye roll from Sherlock and cheers from the Ravenclaws who were looking for their fearless leader to join in the festivities.

Several hours later, the party had finally wound down. Sherlock had retreated to the safety of the dormitory long ago, and was reading over a spellbook. John collapsed onto his bed, which sat next to Sherlock's.

"That's a new record for you."

"Hmmmm?"

"You socialized for nearly two hours; you usually only last thirty minutes," John said turning onto his side to face his friend.

"Gold star for me," Sherlock replied, still intent on his book.

"Thanks for coming today."

"Of course. I couldn't pass up the chance to see you in all your glory," Sherlock replied sarcastically.

"Seriously, Sherlock. Thanks." Sherlock looked up from the pages and gave John a small, genuine smile.

"You're welcome. It wasn't an entire waste of my afternoon."

"Oh really?"

"No. I got a new case." John groaned.

"This does not become a case until we have more information, Sherlock. I don't want you and Molly and Sarah looking at me like I'm a dead man walking."

"Fine," Sherlock replied sulkily. "But when we discover it wasn't an accident…"

"If," John corrected. "If, we find out it wasn't an accident, you can pursue this mystery to your heart's content. Now, I am going to bed. Goodnight, Sherlock."

"Goodnight John." John turned off the light and dove under the covers, placing his wand (cypress and unicorn hair, 26.5 centimeters) on the bedside table. A few minutes later, Sherlock spoke.

"I'm glad that Bludger didn't smash into your skull and blow your brains into the stands."

"Me too. Now goodnight for real," John replied unfazed.

"It would have created quite a mess, and I just bought this sweater," Sherlock added, grinning behind the pages of his book.

John responded by throwing his extra pillow at Sherlock's head. Sherlock began to chortle, quietly. John joined in and soon they were laughing so hard they were almost crying. They carried on like that until the other boys told them to shut up and go to sleep.

Both boys stifled their laughter and obeyed their classmates' command, worries pushed aside until the morning.