Disclaimer: I don't own any of this except the words themselves.

And yes it has probably been done to the ground, but I wanted to have a go. Which is what fan fiction is for I suppose.

Reviews would be lovely.

Chapter One

To Gryffindor and Slytherin we go.

Sherlock Holmes was sorted into Slytherin house barely moments after the hat touched his head. It had debated for the briefest of seconds of putting the intelligent boy into Ravenclaw but settled on Slytherin. The younger Holmes took the hat off of his head, caught his brother's eye, smirked and strolled over to the Slytherin table.

Eyes followed him, the Holmes family was a very well known pureblood family. That had switched between the intelligence of Ravenclaw and the ambition of Slytherin for years. The elder Holmes, a newly made prefect was also in the house of the cunning.

Or so said the boy whispering in John's ear as they nervously waited for their names to be called for the sorting. The boy whispering to him was Mike Stamford, hoping to be sorted into Gryffindor. How he knew the Holmes boy John had no idea, but his eyes watched the curly haired Slytherin as he sat down at the table before turning his attention back to the sorting as Molly Hooper went up, and headed to Hufflepuff amongst a bout of applause.

John bit down on his lip, worried. He wasn't sure what house he wanted to be in, or perhaps he did and didn't want to say so in case he was put in the wrong one. His elder sister Harriet was a Gryffindor, and he had to admit he wouldn't mind ending up in the house of the brave. From what his sister and Mike had said he knew point blank that he didn't want to end up in Slytherin. The war was still recent, and lingered in the minds of the wizarding world, its taint still having its hold on the house.

Mike went to Gryffindor just as he hoped, and some people later John followed him, relieved that he had a friend in his house already, and happy to be in the same house as his sister. He settled down next to Mike, half of his nerves settling as he looked up and down the table at his house mates as Professor McGonagall stood up to great her students. She seemed nice, John thought eyeing her, though she had a look that promised punishment if you crossed her. John hoped her never would. Though being a member of Gryffindor house, meant that he probably would. Gryffindors were very good at ending up in the headmistresses office.

The houses were dismissed and Gryffindor's prefect Jennifer Wilson ushered the first years towards the doors which they reached at the same time as the Slytherins, causing it to clog up. Although either house could have stopped to allow the other through, neither did. Gryffindors and Slytherins were like that. Or so Mike said. He seemed to know a lot about Hogwarts.

"Oh, hello Sherlock," he said as the Slytherin boy was now standing next to them, waiting to get through the doorway.

Sherlock turned at the mention of his name. "Hello Mike," he said stiffly as if he didn't think very much of the boy. His eyes drifted to John.

"John Watson," John said.

"Yes," was Sherlock's reply. John frowned. And was about to ask but Sherlock apprehended his question and answered it for him. "I unlike apparently the rest of the school paid attention to the sorting. John Watson, Gryffindor, I'd say a Muggleborn but with a sibling at Hogwarts, presumably also in Gryffindor house."

John blinked. And there was a clearing which Sherlock slipped through without another word. John turned to Mike who shook his head. "You haven't seen anything yet," he said cheerfully as they also got out of the clogged hall.

"But, how?" John stuttered.

Mike just shrugged. "Don't ask me, but on the scale of things him knowing you have a sibling isn't that big."

"He knew I was a Muggleborn."

Mike shrugged once more. "Don't ask me how he does it, but he does," his eyes lit up suddenly. "I can't wait till I see the teachers reactions," he chuckled. "They won't like it very much."

"Like what?" John asked as they followed their prefect up the stairs with gasps of wonder. Even the Purebloods had hardly seen anything like it.

"He can tell you your life story just by looking at you, or he will be able to one day. You just watch John."

John did.

Or rather, he tried to. The excitement of Hogwarts pushed Sherlock Holmes firmly out of his mind. He was too busy learning the patterns of the staircases, and the fastest way to get from class to class without somehow ending up on the wrong side of the school.

The first class of which he was reminded of Sherlock was the third day of the term in transfiguration. The teacher was Professor Hudson, also the newly made head of Gryffindor house since McGonagall became headmistress. Mike, John and another boy in their dorm called Carl Powers sat in the back corner of the room.

Professor Hudson did the roll and it was the boy's bored 'here' that brought Sherlock Holmes back to John's attention. He was sitting in the other back corner of the room, his eyes watchful following the sound of the student's calling as their name was read off the roll. John wondered if he knew the whole year level yet.

He sat on his own, the spot next to him empty. Which John found odd if the boy was a pureblood, wouldn't he know people already. But the empty space beside him didn't seem to bother him much, he watched the teacher with an interesting mix of rapt attention and managing to appear bored at the same time.

Sherlock glanced sideways, seeming to notice the boy staring at him, he watched John for a few long moments, smirked and turned his attention back to Professor Hudson.

The bell rang and John grabbed his books, and went to accost Sherlock about how he knew he was muggleborn but somehow he had already slipped away.

The next class was potions and while blowing themselves up seemed like a real threat, they weren't too worried. Supposedly the potions teacher was nice, even for head of Slytherin. Beside, they were Gryffindors and by Gryffindor standards explosions were good.

"What house do we have potions with?" John asked as they headed through the great hall and towards the dungeons.

"Slytherin I think," Mike said.

Carl made a disgruntled noise. "We just had transfiguration with them," he protested, as if that would make any difference at all. But it had caught John's attention. Sherlock Holmes was in this class.

Though once more he managed to slip out quickly whilst the rest of the class gathered their books. A few days later John was about to give up on trying to catch him before he left the room, when at the end of transfiguration Sherlock strolled over to John's desk and seemingly picked up one of his books without noticing it.

"You have a question," he said to John, it was a statement not a question. "Ask it. How?" as John had opened his mouth to say exactly that, 'how?'. "You've been continuously staring at me in every class we have together," John went pink. "And frowning, you are trying to puzzle something out. So ask your question, even if I already know what it is." He was flicking through John's book.

Behind John, Mike gave a snort of amusement. "How," John started. "Did you-"

Sherlock gave an audible sigh, as if John was purposely taking too long to figure out how to ask the question. "Did I know about your sibling and blood status?" John nodded dumbly. "Muggleborns you can spot a mile away their first day at Hogwarts, the purebloods fit right even, there is a slight bit of awe in their expression. It is quite grand even with the magic they are used to.

"Muggleborns are completely overwhelmed. Added to the fact that Mike here was whispering in you're the whole time and he knows Hogwarts well enough, older siblings will do that to you. But yours didn't, I guess you are on bad terms with him."

"How do you know about my sibling at all?" John demanded, excusing the fact that Sherlock had gotten the gender of his sister wrong.

Sherlock smiled, but it didn't appear very warm. Most of the class had left at this point, Carl and Mike hanging around for John. Professor Hudson packing up. "Your relief at getting placed into Gryffindor, it might have just been Mike here but your eyes searched the table as you went to sit down. Looking for someone, I'd say a relative, presumably a sibling if you are muggleborn. And your book just confirmed that," he placed John's book back onto the table. Open it read on the cover 'Harry Watson' with the name crossed out and John's scrawled underneath.

John stared. "Woah," he said. "Brilliant," Sherlock smiled. "But Harry is a girl."

"Ah, gender neutral names," he wrinkled his nose. "Or nickname. Harriet?"

"Harriet," John confirmed.

Sherlock nodded firmly. "Try not to watch people too obviously Watson. Puts people on alert," and with that he turned and left. John blinked after him, struggling to find a word to say.

From the front of the room Professor Hudson laughed, and the three Gryffindor boys turned to face her. She smiled at them. "Oh that Sherlock Holmes," she said with an amused shake of her head. "Off you go boys, you'll miss lunch."

They did not need to be told twice. But John thought of Sherlock the whole way.

Oh that Sherlock Holmes indeed.