The Inter-House Challenge: also known as the bane of John Watson's existence. He turned the card over in his hands once more- emerald green, the stock heavy- and eyed the spidery silver scrawl on it with more trepidation than seemed reasonable. A lot of other boys were mentoring Slytherins, so why should he be so nervous?

John sat down on the edge of his bed, the card in his hands, and stared at the name written there. If he were honest with himself, he knew he wasn't worried because the boy was a Slytherin, or a pureblood, or wildly wealthy. He was worried because the boy was Sherlock Holmes.

John had been aware of Sherlock, on some level, since Sherlock's first day at Hogwarts. John had been a second-year, secure and content with his seat on the Gryffindor bench, and he'd known as soon as he saw Sherlock approach the hat that the wild-haired boy at the front of the room would not be joining him. There was some debate, from the people who knew his family (which, considering the Holmes name was one of the oldest in Wizarding lineage, was most everyone), about whether Sherlock would be a Ravenclaw or a Slytherin. The eldest Holmes boy, Mycroft, had been a groomed for the dungeon-dwelling house since infancy, but Sherlock…John had heard odd things about Sherlock. That he was intelligent to the point of near-omniscience. That he had an awful temper and a surly attitude, but he was never pointlessly cruel and seemed to actually enjoy helping people (though, according to the people that knew him, it was not the pleasure of charity but the thrill of the puzzle that drew Sherlock's attention). People wondered…but in the end Sherlock joined his brother (a sixth year, at the time) at the Slytherin table, looking none too pleased. And that was that.

Later, John heard rumors about Sherlock. That he'd helped the headmaster find some secret tunnel that had posed a security risk to the castle. That he'd been in a fight with a couple of other Slytherin boys (the name Sebastian Wilkes came up, among others) because they'd called him a freak. That he'd gotten cheeky with a professor and earned himself a year's worth of weekend detentions. That he'd caught out a group of seventh-years who were (rather cleverly, John thought) cheating on their N.E.W.T.s and reported them at once. Despite being a year and an entire castle apart, John found that he'd heard quite a lot about Sherlock Holmes over the years. Now, as he twirled the green card bearing the boy's name on it between his index fingers, he wondered what Sherlock had heard of him.

x

The Inter-House Challenge had been devised shortly after the "Potter Era", as it was known in Hogwarts history. The idea was simple enough: each student would be given, during their O.W.L. year, a mentor in the form of a sixth-year student. To promote inter-house unity, that mentor would be from a differing house. Easy enough. Most students got on well enough with their mentors (John certainly had, though Hufflepuff Molly Hooper had hardly given him a challenge) and the time was spent companionably enough. During the year, mentor and student would meet occasionally to work on their end-of-year Challenge Project, which could be absolutely anything of their devising so long as the students had worked together on it. The fifth-year student was given an O.W.L. mark for the project; the sixth-year student had to write and turn in a report to the headmaster. Best project of the year won a trophy. Couldn't have been more straightforward.

Except…

John couldn't help but think, as he pressed the card with Sherlock's name on it between his palms, that his mentor project was not going to be straightforward at all. Not in the least.

x

The next morning, an assembly of fifth and sixth year students was called in the Great Hall. It was time for the fifth-years to meet their mentors. John entered the cavernous hall with anxiety sitting like a stone in his stomach. He had to fight the urge to tug at his jumper or smooth his fringe as he crossed the room and went to where he'd seen Sherlock Holmes sitting.

Sherlock, for his part, didn't seem nervous at all. He was pale, certainly, but from what John had seen of him…well, the boy was always pale, the fact only accentuated by the mess of dark unruly curls piled atop his head. As John got closer he noticed there was something very posh about Sherlock's cheekbones and his neatly pressed clothes, which in turn only made him more nervous. Still, John wasn't a Gryffindor for no good reason. He had never let nerves get the best of him before, and he certainly wasn't planning to start anytime soon.

"John Watson," he said, sticking out his hand.

The younger boy eyed him the way someone might look at an unexpected stain on a new dress-shirt. "Yes," he said, his voice surprisingly deep and unsurprisingly brisk, "I'm aware." He made no move to introduce himself, nor did he take John's hand.

John cleared his throat and passed his unwelcome hand over his hair. "Right. Well. I'm your mentor."

"Obviously." Sherlock couldn't have sounded more bored if he tried, John thought.

For a moment they were silent: John, standing awkwardly with his hands clasped behind his back and his mouth pulled into a frown; Sherlock, with his strange-coloured eyes narrowed and sweeping over every inch of John's small frame. Finally, Sherlock broke the silence, drawling, "Well, John, you're in luck. I'm not in any need of a mentor. I hereby relieve you of your duties."

"You…what?" John shook his head. "You can't just…well, you have to have a mentor. It's a school rule. You can't just…dismiss me." In truth, he was a little offended. Was he not good enough for Sherlock or something? Certainly he wasn't in prime physical condition (a Quidditch injury and a botched healing had done a number on his shoulder, and he sometimes limped a little from the leg he'd broken as a kid) and maybe he wasn't a genius or some rich prat, but John prided himself on being pretty damn likeable. So what was this Holmes kid's deal?

"I can, and I did," Sherlock said carelessly, turning his attention to the book that sat nested in his lap. He glanced up, just for a moment, and met John's eyes before dropping his gaze back to the back and muttering, "You can't be of any use to me."

"You don't even know me," John said automatically, his left hand twitching. (It was an odd habit of John's, flexing the fingers of his dominant hand whenever he was stressed or worried, but it helped somehow and he'd long since decided that was all that counted.) He straightened his back and lifted his chin defiantly, and Sherlock chuckled.

"All right," Sherlock said, steepling his hands beneath his chin, "I know you're a sixth-year, obviously, and a Gryffindor. I know you've got an older brother and you don't get on very well, possibly because he's a drinker but probably because he's a Muggle and he resents you for being different. You're Muggleborn and not close with your parents, either, I imagine because your family is poor and you habitually argue over money. You like Muggle sport and you wish you were good enough to play for Gryffindor's Quidditch team. You're not, however, so you settle for a summer football league back home. You've got a…dog, yes, not a crup, but it's small. Terrier, I'd say, and you're not overly fond of it either so I'd guess it belongs to your brother. The injury to your shoulder is quite real and probably the reason you'll never play Quidditch in any actual capacity; the injury to your leg mystifies magical healers, but your Muggle doctor thinks it's psychosomatic, the events surrounding it having been quite traumatic to you. He's quite correct, I'm afraid." Smiling smugly, Sherlock stood and tucked his book under his arm. Standing, Sherlock was nearly a foot taller than John, but that didn't stop John from folding his arms over his chest and fixing Sherlock with an unwavering stare. Moving to walk away, Sherlock sighed, "That's enough to be going on, don't you think?"

"And all of that disqualifies me from being your mentor why exactly?"

Sherlock froze in his tracks. He spun slowly and met John's eyes with a ferocity that took the older boy back. "You're exceedingly ordinary," Sherlock said slowly, his jaw clenched, "and not my problem. I've better things to do than babysit a future healer with a psychosomatic limp. Have a lovely day, John, and piss off."

"You're wrong about me," John growled. He didn't know why he cared what this rotten snake thought of him, exactly…only that he did care. Maybe because so much of what Sherlock had said about him was true (unnervingly so) but the fundamentals were completely wrong. At least, John hoped they were wrong. He found that he didn't want Sherlock to think he was ordinary. Because he didn't think Sherlock was ordinary at all; he thought Sherlock was absolutely brilliant (if a bit mad, and rude).

To John's surprise, Sherlock looked him over again and then sighed so loudly John imagined the entire student body had heard him. "Fine," Sherlock spat, tapping his long fingers on his folded arm, "then prove it. Meet me tomorrow evening, just before supper bell, outside the dungeons." He seemed to relax some, though he obviously still didn't think very highly of John, and said, "If anyone asks what you're doing, tell them you're waiting for Sherlock Holmes." And then, to John's astonishment, he actually winked and dashed away, his long legs carrying him across the room and out of the hall in a flash.