No one can figure him out.

Oh, he can figure them out, of course. He can look at you and tell you your entire history from the folds of your cloak or the dents on your wand. He's the smartest person anyone at Hogwarts has ever met, but he's not in Ravenclaw, he's in Slytherin. He's a Slytherin, but his best friend is a Gryffindor. More than his best friend - after he and John met, the Sorting Hat seriously started wondering whether he had been wrong in not sorting both of the loners with trust issues into Hufflepuff, because even people deeply in love aren't usually that loyal to each other. Even the famed Boy Who Lived and his best friends didn't have that connection. He is skilled at school, but only when he feels like it; sometimes he doesn't attend classes for days on end. His long limbs hanging over the edges of John's bed (he has, of course, figured out the password to the Gryffindor common room), he aimlessly hurls jinxes at the dorm wall.

"Write up my astronomy paper, will you John?" he drawls, flicking his wand upwards. John immediately hurries to put out the flame on the wooden wall.

"Write it yourself, you lazy bum."

Sherlock sighs overdramatically. "Dull," he announces, his tongue lingering on the final 'L.' There's a long pause as John deliberately pretends his friend isn't there. Finally Sherlock speaks again. "It's really a matter of who cares more."

"What the hell do you mean?"

"Well, I really couldn't care less about Astronomy, and as I really don't have the necessary information to finish that paper -"

"Well, maybe if you hadn't skipped class for the past week-" John starts to huff, but Sherlock continues speaking as if there hasn't been an interruption.

"-and can't be bothered to go look it up, I'm certainly not going to write that paper. And if I don't write it, I'll probably fail Astronomy, and if I fail another class, I'll probably get kicked out, and as you seem to care a great deal more about my well-being than I do, its in your best interest to write my paper for me."

John glares. "And what if I get caught?"

"You won't." Sherlock says with certainty.

"How do you know?"

"You've never gotten caught before."

And John sighs and pulls out his quill.

Yes, no one can figure Sherlock out, not even John. John is two years below Sherlock, and when he came to the school, his fellow Quidditch team members all told him to stay away from the enigmatic Slytherin. Sally was especially vehement. John knows why they dislike his friend. After all, Sherlock's said so himself: he's a high-functioning sociopath. But he's attached himself to a few people: Greg Lestrade, the captain of the Hufflepuff Quidditch team and Head Boy. Sherlock has helped him figure out quite of a few of Hogwart's never-ending mysteries. Professor Hudson, the new herbology professor and head of Hufflepuff house. Sherlock helped prove to the Ministry that her husband was a Death Eater. Now he's in Azkaban, and he and John often stop by her room to have tea on the weekends. Then, of course, there is John himself. He's one of the bravest Gryffindor has seen in a while, but he's a fairly ordinary guy, and no one is quite sure why Sherlock has latched himself onto the younger boy so much.

No one can figure Sherlock out.

And no one can figure out exactly what he's figured out about John Watson.

Not even Sherlock.