Chapter 1 - The Sight of a Friendly Face

Disclaimer: I do not own Harry Potter or Sherlock. But I love them! :D

King's Cross station was as busy as ever - travelers rushed from platform to platform, luggage in tow, hoping to make their train on time; massive machines pulled along rails to their destinations, the echoes and groans of their operation dominating the already fairly noisy space; and people, people were everywhere, all engaged in conversations, laughing, talking, even crying.

In the midst of this activity, it would have been very easy to miss a young boy limping across the crowded platform, luggage cart in tow. In fact, nearly everyone did - and John Watson wasn't surprised in the least. After all, he didn't cut a particularly important or striking figure. He wasn't entirely sure he knew what he was doing himself.

Come to mention it, that probably wasn't a good thing. His father had just dropped him off without a word of advice, or even a well-wishing. It was up to him to catch his train now, and he was afraid his chances of doing so were slimming by the minute. Probably time to make sure he had all the details in order.

Finding a relatively calm eddy amongst the swirling stream of people, he set his cane aside, leaning against the handle of his cart, and pulled the mysterious ticket from his jacket pocket. He fingered it carefully, almost as if expecting it to suddenly vanish or for the number written across the front to change. It wouldn't be wholly unexpected, in truth.

Platform Nine and Three-Quarters.

Well, it hadn't changed on him, at the least. Of course, that didn't mean it made any more sense to him now than it had this morning. Perhaps even less so. At least now he didn't have his sister laughing at him.

"Nine and Three-Quarters? Oh, this school's a right place for you, John - a looney bin! If you can get there. Are you sure it's a train? To get to this... Pig-Something place? I was under the impression you might travel by unicorn"

"Actually, I think the unicorns live in the forest. I don't think they'd be very at home in a London train station..."

At that point, she'd burst out laughing and he'd thought it best to give it up. John's ears burned slightly at the memory. But now was not the time to recall Harry's ridicule - it was nearly eleven o'clock , and he still had to figure out exactly how he was going to get on this elusive train to Hogwarts.

He looked up again, hoping that he might somehow suddenly understand the meaning of the fractional platform number. Was he supposed to wait between the two? Was there some secret passage or something, some way that he hadn't been told about? Would he ever get in?

John had already tried asking one of the platform attendants, but his results had been discouraging - not only did the woman tell him to "Run along and find his family", but he wasn't even entirely sure she'd heard his question. Apparently a shabby-looking young boy with his school things wasn't enough to merit a response.

But time was growing short, so he resolved to try again - this time he'd search out a fellow traveler. Perhaps with luck they'd be headed for the mysterious platform as well. Surely there had to be some other students here. And their parents! Someone would know.

Unfortunately, three people later, he was well and truly discouraged. No matter how tactful his questions may have been ("Excuse me, are there any other platforms around here? Perhaps some oddly numbered ones?") he always got the same response. So far he'd been told to "stop joking about", "bother someone else", and "take things seriously, young man - this is train station, not a primary school". He supposed his appearance wasn't helping him - it was doubtful most of these people actually thought he was his full eleven years of age. But that couldn't exactly be helped, so he thought it rather unfair all the same.

To be honest, John was beginning to wonder if this mysterious school for wizards even existed to begin with. He sure hadn't heard of it before. But then again, he family was most certainly non-magical. And he'd gone and bought supplies in Diagon Alley, hadn't he? After his father dropped him off at the Leaky Cauldron? Sure, he'd needed some help, but that had been real enough!

He was mustering up the courage to try one last time when his trolley slid out from under his right arm. He tried to catch himself, but his bad leg stubbornly refused and he ended up - quite embarrassingly - on the floor.

"Are you alright?" a concerned voice asked from behind. John looked up, face burning, to see a tall man with messy black hair and glasses looking down in concern. He was obviously the speaker, but next to him was a boy only slightly older than himself. For some reason, said boy had dark purple hair, which clashed horribly with his greenish-brown jacket. But they both looked friendly enough.

"Just fine," John said sheepishly. He glanced about for his cane, which had flown a good foot or two away. The stranger, noticing this, bent down to grab it and hand it to him.

"Sorry about that," said John, pulling himself from the floor.

"Oh, no problem. If you're sure you're not hurt, of course," the man said. He looked at John more closely for a moment, taking in (John could only assume) the boy's rather secondhand appearance and injury. He was sure he looked far from impressive. John bit his lip slightly, wondering if asking this man for directions would be appropriate - or even worth his time.

"Are you all alone?" the man asked eventually, having finished his cursory examination. The question seemed primarily out of concern, which John found to be another encouraging sign. This stranger seemed trustworthy, to say the least.

"Well... my dad and sister dropped me off a bit ago so I could catch the train to school. But I'm afraid I seem to have gotten myself lost or something."

"Train to school?" the man asked smiling. "Teddy here's doing the same!"

The purple-haired boy gave John a wide but friendly smile. "Might I ask what school?"

"Er..." John wondered if they would laugh at him like all the others. Then again, if he never tried, he might be stuck here on the platform for... well, for as long as it took for his dad to realize he'd never made it to school. That would be incredibly embarrassing. (As if this whole fiasco wasn't already.) And they were certainly nicer than everyone else he'd asked.

"Well, it's a private school, I think. I'm not sure exactly where it is..." he began carefully. "And the platform is rather... oddly numbered. I was wondering if there might be a mistake...?"

The stranger just smiled, exchanging a knowing glance with the boy at his side - it had just occurred to John that he didn't know the man's name. That, and Teddy seemed a bit too old to be his son. Who was he, then? Could he trust these people?

"Nine and three-quarters?" Teddy asked, smirking a bit - though not in an unfriendly way.

John breathed an immense sigh of relief. "Yes! That's the one! Do you know how to get there?"

"Of course we do!" the man said cheerfully. "That's where we're headed as well. Teddy's going to be a second year at Hogwarts. And I'm assuming it's your first?"

John nodded. "Yes, but I'm really not sure about it all. I'd never even heard of... of wizards and magic and things until I got my letter."

"Oh, I was the same way," the stranger said, still smiling. "I'm afraid I didn't catch your name. I'm Harry, Harry Potter, and this is Teddy Lupin. He's a family friend."

"John Watson," he said in return, still relieved by the friendly exchange. "Thanks for your help, Mr. Potter."

He hoped the man didn't ask him to call him Harry - that would remind him too much of his sister, and just be rather awkward. They hadn't exactly been on good terms since the accident. Or even before it.

But this Harry just smiled. "You're welcome. Now, let's get to the platform, shall we? Show him how it's done, Teddy."

John looked towards the older boy, who grinned and tightened his hold on his luggage cart. Seconds later, he was racing towards the barrier between the platforms.

"He's going to run into the wall!" John said, alarmed.

Mr. Potter laughed. "Looks like it, doesn't it? Just watch."

John complied, gasping as the boy vanished into thin air.

"But where did he go?" he asked, turning to the dark-haired man. He was sure his face looked ridiculous right now.

"The platform, of course!" he noticed John's incredulity and laughed. "I know, it makes no sense. But honestly, just run straight at the barrier. I promise no injuries will result. It's sort of like a secret passage."

John looked in alarm at the wall, back at Mr. Potter, and at his luggage cart. His eyes eventually settled on his cane and he frowned.

"You don't have to run, do you? For it to work?" he asked.

"Well, no, but it certainly keeps you from being nervous. I'd suggest... er, never mind," the man trailed off a bit, realization dawning rather quickly. "You'll be fine either way."

John nodded, setting his cane on the cart and tightening his grip on the handle. Cautiously, he advanced towards the barrier at a pace somewhere between a speedwalk and a slow limp. Looking back, he saw Mr. Potter's encouraging grin, and then - then everything changed. He'd hit the wall when he wasn't looking, and as he brought his head back around, he realized he was somewhere else entirely. A sign above his head read Platform Nine and Three-Quarters and a massive red engine steamed along the tracks.

"John!" a voice called. He looked to his right and saw Teddy, now standing with another boy, waving at him. But something was different...

"Your hair!" he said, trying to limp over before giving up and grabbing his cane from the top of the cart.

Teddy, whose head was now a shade of midnight blue, didn't respond to this. Instead, he gestured towards his new companion.

"John, this Greg. He's another second year. Greg, this is John Watson - he's new. Helped him out a bit on the platform."

Greg extended his hand. "Nice to meet you, then!"

In any other circumstance, John would have accepted the handshake readily, but at the moment he was still transfixed by the bizarrity of finding a train platform behind a wall, complete with a massive steam engine. That, and the enigma that was Teddy Lupin's hair.

"There's a train!" he eventually said. "How is there a train? How is there a platform?"

Greg just lowered his hand a bit and grinned. "Muggle-born, then?"

John was shaken from his confusion by the unfamiliar word. Muggle? Oh, right, non-magical. He'd heard that one a lot whilst he did his before-school shopping. Looks like he'd definitely need to get used to it.

"Er... yes. Sorry. Nice to meet you, Greg...?"

"Lestrade. Greg Lestrade. And don't worry about it! My mum was a Muggle-born too. Can't imagine the confusion."

The boy extended his hand once again. This time, the handshake was successful. Just as John was about to ask about Teddy's hair again, Mr. Potter appeared next to them. He'd made his way through the platform, as well.

"Ready, boys?"

Greg, John, and Teddy all nodded - though John later wondered if he'd actually been included in that question. Either way, the man gave them all a grin.

"Well, good luck! Say hello to Neville for me. I'm expecting owls, Teddy - and not from the headmistress."

"That was an accident!" Greg protested. Next to him, Teddy just grinned.

"Yes, well, if you plan on sneaking out at night I can't discourage you - not with my track record, at least. Just don't get caught this time." Harry looked John in the eyes. "And you - well, you just enjoy yourself. You'll do great, I'm sure. In fact, I'm expecting to hear good things about John Watson - and his friends."

John blushed, wondering why exactly this man was so ready to assume he'd achieve anything. "Thanks again, Mr. Potter."

"No problem! Good luck at Hogwarts. It's a fantastic school."

At that moment, the whistle for the train rang out rather suddenly. Next to him, Greg and Teddy both jumped at the sudden sound, then laughed, grabbing their trolleys and racing towards the massive vehicle. It took John a few moments to gather himself and get moving properly, but in the end he found himself heading towards the train as well, albeit at a slower pace than the older boys. The last he saw before he was swept in the crowd was Mr. Potter, waving to the three of them.

His heart began to beat a little faster, though he wasn't sure if it was from apprehension or excitement. Probably a bit of both.

And so the adventure begins...

A/N - Hello, readers! I'm happy to announce my next big multi-chapter fic, A Study in Gold and Scarlet! And before I get too deep into things, I'd be interested in getting a beta for this one. Preferably with decent knowledge of both Sherlock (including ACD works) and Harry Potter. Any interest?

In my author's notes, I'll be telling you a lot about my thought process - everything from character interactions and head-canons to my heavily researched ideas on the wands or houses of each character. Because that's how I roll. For now I don't have too much to say, except for this - I personally like to imagine Harry helping out future students on the platform, even in a purely HP continuity. The way the Weasley's did for him. It just seems like something he would do (and is somewhat adorable, in my opinion).

Ah, and for anyone interested, this story is supposed to begin in 2010, which is indeed Teddy's second year according to J.K. Rowling's timeline. (It's also the year that Sherlock first aired. No coincidence. :D) It'll also reach into 2011, since it's supposed to cover an entire year at the school.

The chapter title comes from A Study in Scarlet, specifically a quote of Watson's. ("The sight of a friendly face in the great wilderness of London is a pleasant thing indeed to a lonely man.")

I'm planning on working on this story for Camp NaNoWriMo this April (look it up, if you don't know what that means - it's fantastic for word counts), so if I don't update, please do bother me about it. Means I'm getting lazy.

Reviews and such are always appreciated. Hope to update soon!