Title: Harry Potter of Baker Street

Author: Dayja

Beta/Britpicker: Kulfold

Summary: Sherlock Holmes discovers family he never knew he had, and John Watson finds a child living in the cupboard.

Rating: PG13

Genre: AU, crossover between Harry Potter and BBC Sherlock

Warnings: references to child abuse, quite likely references to dead bodies and body parts as might be expected with a pair of men who solve crimes. If anything worse comes up, I'll let you know. This is a WIP. I cannot promise quick updates (My attention span can be intense when I start a project, but also short. If it helps, each chapter could almost be considered a stand alone, but I do intend to continue it.)

Spoilers: For the Harry Potter books…only the first one really in this chapter, but references to all seven might come up as I go along. With Sherlock, no real spoilers yet, again, but as I go along there will likely be references to the tv series. I can promise that I won't be spoiling for anything that hasn't already been shown on TV in the UK.

Disclaimer: I do not own/am not associated with Harry Potter or Sherlock. I make no money from this. Now, if you haven't been scared away by the above, on to the story.

AN: Now helpfully betaed and brit-picked by Kulfold! Anything you still find wrong is probably me being stubborn about my bad grammar or tendency to make up words that I think should exist but don't. Or it's a chapter Kulfold hasn't gotten to yet. But this first chapter at last should be improved.

Chapter 1

John Watson was used to finding the unusual when he came home. Body parts in the fridge, poisons tucked away in former food containers, chemistry experiments bubbling and fuming on the kitchen table…this was normal and to be expected, if not encouraged. Coming home to find a child sitting alert but silent, huddled in the cupboard where John had hoped to find the tea he had taken to hiding in the hopes that Sherlock wouldn't take it upon himself to contaminate it with his experiments…that was new.

The evening had begun normally and John was halfway through his traditional greeting with Sherlock. John asked Sherlock after his day, mostly out of self defense so he would know the little things like that the container labeled 'sugar' now contained arsenic, or whatever else Sherlock had decided was an appropriate substitute in the kitchen. And then Sherlock would tell John about John's day. They were halfway through this greeting, when John went for the tea and saw the child.

It was a boy, probably, judging from the dragon on his shirt, who was somewhere in the range of three or four years of age. If that wasn't enough, he had black hair that stuck out all over and huge green eyes that stared solemnly at the two of them with a sharp intensity. John could hardly be blamed, therefore, when his first thought was something like, 'oh god, he's acquired a son.' What he said out loud was, "Sherlock…why is there a small boy sitting in the cupboard?"

"What?" Sherlock looked over at the boy with some surprise, as though only just realising he was there. "Oh, right. A man brought him while you were out. I'm his new guardian."

John blinked. He looked at Sherlock. Sherlock looked back. John looked at the boy. The boy watched them both, still silent and apparently unperturbed by his being left alone with a stranger. John opened his mouth, then closed it again. The obvious response was of course, who in their right mind would leave you with a small child? Or perhaps, why on earth did you think it appropriate to stick him in the cupboard? What actually came out was, "So what's his name?" Sherlock's forehead wrinkled up as he considered this.

"Horton?" he suggested, "Henry?" At John's unamused look, Sherlock gave a dismissive wave of his hand towards the mantle. "He came with a note. You can read it if you like."

"I thought you said a man brought him. Didn't you ask any questions?"

"I was busy," Sherlock answered defensively, "and he was a bit distracted himself." From which John took the answer to be 'no, I didn't ask any questions' even as Sherlock explained what important experiment he had been conducting. By the time Sherlock had gotten to how the old man had been wandering around the flat and pointing his stick about while chanting, John had stopped listening. Instead, he resigned himself to the insanity of his life and went to look at the note. It was unexpectedly thick, not because it was long but because it was written on some kind of medieval looking parchment. Even the writing had a bit of flair to it, done with calligraphy in emerald green ink.

'Mr. Sherlock Holmes,' he read, 'I do not know if you are aware, but your aunt Lily Potter née Evans and her husband James Potter died three years ago on All Hallows Eve, being murdered by a very evil man. Their son, Harry Potter, was taken to his aunt Petunia Dursley née Evans to be raised in her family alongside her own son. It has since come to our attention that the Dursley family is an unsuitable environment in which to leave him. As his situation is somewhat delicate, due to the nature of his parent's death and to a group of those who would wish the child harm, we have searched you out as his only living relative. It is very important that young Harry be placed with family, as there is protection that can be had through your blood and there are still those out there who would wish him harm.

We are aware that suddenly taking on a child can be a bit of a burden. As such, a small sum amounting to five hundred pounds will be sent to you monthly to aid in his upkeep. You can also expect social services to monitor you as you settle into your new family role. If you do require more assistance, your brother Mycroft Holmes will know how to contact us.

Yours Sincerely,
Albus Dumbledore'

John looked up from the letter. He frowned. This made no sense at all. That wasn't how social services worked; they couldn't just bring the boy over and drop him off, not even with the vague threat of coming back to check up on them. Besides, Sherlock couldn't be his only living relative. Even if Sherlock's parents were dead, a fact which John was naturally reluctant to ask questions about, Sherlock had an older brother who they obviously knew about as he was mentioned by name. Perhaps they had gone to Mycroft first and Mycroft had arranged for Harry Potter to come there? That would explain some of the unusual procedures, if not all the references to blood and people out there wanting the boy dead. Or was this a sort of witness protection thing?

"So he's your cousin?" John asked at last, hoping he could get at least that much verified.

"So the old man said," Sherlock agreed. "Interesting allegation as he is apparently accusing my mother of infidelity and, from what I could gather, my grandfather of infidelity as well. Apparently there was a son no one knew about. I have yet to verify anything of course."

"Do you think Mycroft would know?" John asked, watching Sherlock closely. Sherlock appeared completely unconcerned that he might be the son of someone other than Mr. Holmes and, in fact, didn't look particularly put out that he had been suddenly saddled with a small child. He seemed too unconcerned.

"You are going to actually do something about Harry, right?" John asked, frowning slightly, "You do know you can't just leave him sitting in the cupboard for the rest of his life?"

"Of course not," Sherlock answered, "I've already texted Mycroft." Sherlock still wasn't looking towards either of them and for the first time it occurred to John that maybe Sherlock was a bit freaked out over this after all. He was so out of his depth he didn't even begin to know how to respond. So, being Sherlock, he ignored the issue and pretended it wasn't there. Still feeling a bit shell-shocked himself, John decided it was time to face the issue head on. He approached the child, kneeling awkwardly on the ground to be closer to his level. The boy stared, unmoving.

"Hello," John said. The boy stared. "I'm John. What's your name?" The boy stared. Then his mouth moved and sound came out, almost too quiet to be understood. If John hadn't already read what his name was, he might have thought the boy said something like 'Ree Pot'.

"Hello, Harry," John said and gently offered his hand to be shaken. Harry took it hesitantly and smiled shyly. John found himself smiling back.

"Do you know where you are, Harry?" John asked. The boy had to be a bit confused, being thrust into this new environment and left in the care of a man who had apparently been ignoring him for who knows how long. Cautiously, Harry nodded his head.

"Mr. Sherlock is my new uncle," he declared. Then, slowly crawling towards John, he asked, "Are you my new uncle, too?"

"If you want," John answered, a bit cautiously himself, because he still wasn't entirely sure they were really going to keep the little boy who had been more or less dropped on their doorstep. John could not honestly believe that Sherlock was nearly responsible enough to look after a little boy; surely someone would realise that soon and take him away. Still, he couldn't say no when Harry looked so hopeful. Suddenly, Harry's stomach growled.

"Are you hungry, Harry?" John asked, smiling at him. To his surprise, the little boy's eyes teared up.

"I'm sorry," he whispered, huddling in on himself back into the space he had just crawled from.

"It's no problem at all," John told him, "I'm a bit hungry myself. Why don't we…" he started to say something like 'make sandwiches' until he considered the disaster that was the kitchen, and abruptly changed to, "go out?" Harry's eyes grew huge.

"Go out to eat?" he asked. "At a real outside eating place?"

"Er…at a real restaurant, yes," John agreed. Harry smiled hugely at him. "Alright then, we just need your coat…" He turned to look at Sherlock again and asked, "He does have a coat?"

"I think so," Sherlock answered, staring at the two of them with an expression John couldn't read, "There is a bag over there." John looked and found a cloth sack, over which was draped not only Harry's coat but his gloves, hat, and scarf as well.

"Okay then, Harry, let's get you dressed," John announced, and started helping him to bundle up. Sherlock watched. John went to get his own coat and then paused, turning back to Sherlock.

"You are coming," John said, not making it a question, though Sherlock answered with, "Of course, John. I was feeling a bit hungry myself."

The experience of dining out felt a bit surreal; the entire evening felt surreal. He half expected to wake up and discover he was having a bizarre dream in which Sherlock had actually been entrusted with the welfare of a small child.

To Sherlock's utter disgust and Harry's glowing adoration, John took them to McDonalds. Sherlock refused to order anything, despite his earlier divulgence that he was hungry.

"You do know this particular chain keeps their cattle in fields created by the destruction of the rain forest," he muttered, as though that were something that deeply concerned him, when John knew for a fact that the only reason he knew that bit of trivia was that Molly had brought it up once in an ill advised attempt at conversation in the morgue. Then Sherlock went on to talk about mad cow disease, earning more than one annoyed look from the other customers in the line. Harry looked concerned.

"We'll get you the chicken nuggets," John told him, and then gave Sherlock a very stern look before he could explain everything that was wrong with them. Sherlock, thankfully, was silent on the matter. Though he still refused to order.

John took Harry out to the play set in the back of the restaurant, agreeing to hold onto his shoes because Harry obviously felt nervous of leaving them behind unwatched. He seemed reluctant overall to play on it, a bit overawed by the tubes and balls, but John eventually convinced him to try it. Thankfully. Because part of the entire idea behind bringing Harry here was to be able to talk to Sherlock without Harry overhearing.

"Sherlock," John said, "What are you going to do with him?"

"I don't know what you mean," Sherlock answered and the sad part was he really didn't seem to understand. John sighed.

"Small children take work," he said, "they need love and attention and discipline. And he will be yours, not mine or Mrs. Hudson's, even if we can help out. Are you going to be able to handle that?"

"The old man seemed very convinced I could," Sherlock said. "He seemed to think there was nowhere else he could go." Which didn't answer the question at all of course, but did remind John of others he had.

"You do know this is weird?" John asked. "Old men do not usually drop of little boys without any warning, even if you are family. Especially as the home he was in before was deemed unacceptable."

"Which is why I texted Mycroft," Sherlock answered, staring thoughtfully over to where Harry sat in the ball pit, holding a single ball and staring at it while other children jumped and laughed and screamed around him. "Do you think I get to name him?"

"He has a name," John reminded him, a bit warily.

"But you said he was mine. The old man said he was mine. And Harry is a boring name. Besides, won't you get confused?"

"I think I can deal with knowing two people called 'Harry'," John answered dryly. He had certainly coped over the years with sharing his own name with half a dozen of his peers at a time.

"Still…" Sherlock answered, still looking thoughtful.

"So you do intend to keep him, then?" John asked, looking hard at his friend, "You do know if you do, you can't abandon him when he becomes boring."

"I don't know," Sherlock answered, suddenly looking at John with a lost expression, "but they said there isn't anywhere else. You know about children."

"Yes," John agreed slowly, "but I'm just your flatmate. I won't be his parent. Guardian. Whatever."

"You agreed to be his uncle. I heard you."

"That's not the same thing, Sherlock," John answered, "I'm serious. What will you do when you have a case? What about all your experiments?"

"What about them?" Sherlock asked, looking genuinely confused.

"You can't have poisons and dangerous chemicals sitting out with a small child in the house! And you can't rush off and leave him alone at all hours…and no, you can't take a child to crime scenes." Sherlock slowly closed his mouth, frowning petulantly. "For that matter, where is he going to sleep?"

"The old man said he had been sleeping in the cupboard under the stairs."
John opened his mouth. Closed it. Sucked in a deep breath and let it out again, slowly.

"Please tell me you were not planning on emulating his former guardians?"

"Well…it did seem a bit odd…but if he's used to…"

"No, Sherlock!" John cried, his voice firm and slightly aghast, "He was taken away from them, because keeping a child under the stairs is bad."

"Right," Sherlock said slowly, watching John carefully, "So you wouldn't object to him having a room. With a bed. Not a cupboard."

"Of course he should have a…" John trailed off from his righteous indignation at how a child had been treated and looked at Sherlock suspiciously. "Sherlock. What bed did you intend to give him?"

"Well, he can't have my bed. My room is filled with all those dangerous things you were saying he couldn't have. So I thought…"


"You could share. He's small; he wouldn't take up much space."

"He's getting his own room," John insisted firmly, "One that isn't already taken." Sherlock sighed.

"Don't be ridiculous, John. Sleeping on the sofa would be horrible for your shoulder."

"He's not getting my room," John said. Sherlock looked at him. John stared stubbornly back.

"Oh, alright," Sherlock finally said, and John almost relaxed until Sherlock continued with, "You can share my room if you like. Just mind the experiments. And I do hope you don't kick too much in bed."

John stared, finding so many things wrong with that scenario that he didn't even begin to know where to correct Sherlock in his new assumptions. John opened his mouth. Sherlock watched him, smiling pleasantly because he had found the perfect solution to all their problems. John closed his mouth again. He laid his head down on the table and groaned.

"Isn't that rather unhygienic?" Sherlock asked helpfully, eyeing the plastic table with disgust. John's answer was to groan again.

Then their order was finally called and Harry was retrieved from the ball pit, so that was the end of the discussion.

Sherlock, despite his declared disgust with the entire establishment, still stole half the fries.
That night, John did sleep in Sherlock's bed. But he made Sherlock sleep on the sofa.