Disclaimer: I do not own Harry Potter or Doctor Who. Still trying though. Who knows, maybe JK Rowling will give up.

Another inspiration for me was "The De-Aged Doctor" series by Whovian101 on ao3 (I would link it but I can't)

Chapter 2 - Interruptions

The Doctor was standing in King's Cross Station, carrying his trunk behind him. Around him people bustled off to wherever they had to go. He was facing the wall between platforms nine and ten. He glanced down at his ticket again. Then he looked up, steeled himself and ran at the wall. He braced himself waiting for the impact, but it never came. Finally he opened his eyes. In front of him were students and parents and a great, big, red train.

He could hear parents calling to their children who had already gotten onto the train, telling them to send letters, and wishing them a good year. Around him stood more parents some clutching their children, like they didn't want to let them go. To his right he could see a big group of children gathered in a group. They were all ginger. Why couldn't I be ginger? The Doctor though and looked back at the wall he had just come through.

"Fascinating!" He whispered. "It's not teleporting us, and it's not just hidden from view! This is incredible. I think it's folding space over on itself and creating a gateway from one place to another!" He turned expecting to see someone listening to him, but there was no one there. He had gotten so used to Amy and Rory's presence that it was weird without them. His hearts clenched at that and a wave of sadness overcame him for a moment. Then he shook his head, as if to clear the thought away, and moved on from the wall.

He clambered onto the train and pulled his trunk up beside him. He would have to find a compartment that was relatively empty. He was pretty sure that the train ride would be boring and he didn't really want to be dragged into some stupid conversation that he didn't care about.

After walking for a few minutes he stumbled onto a compartment that was almost empty. A boy with black hair sat alone staring out the window.

"Hello! Mind if I sit here?"

Not really waiting for an answer, the Doctor plopped down onto a seat opposite the black haired boy.

"So, I'm the Doctor. I mean John Smith." He corrected. "The Doctor is like my," he paused. "Like my nickname!"

"I'm Harry Potter." The boy said and they shook hands.

Now that the introductions were done the Doctor pulled out "A Guide to Advanced Transfiguration." He flipped to the right page, somewhere in the middle of the book and continued reading.

The train started moving and a few seconds later the compartment door slid open to reveal a red-headed boy.

"Anyone sitting there?" He asked, pointing to the seat next to the Doctor.

Both boys shook their head and the red-haired boy sat down, deliberately not looking at either of them. The door opened again.

"Hey Ron," two identical ginger haired boys said to what the Doctor assumed to be their brother. "Listen, we're going down to the middle of the train — Lee Jordan's got a giant tarantula down there."

"Right." The boy, Ron, mumbled.

"Oh, hello!" The other twin said, noticing the Doctor. "Woah, are you reading 'A Guide to Advanced Transfiguration?' That's a sixth year book!"

The Doctor glanced up. "I'm trying to understand the theory. This is the only book that seems to have it. I mean that's just ridiculous. How are we supposed to learn the magic without understanding how it's done. See, I've got all the others down, but Transfiguration is tricky. Because the ways it's written it sounds like it breaks the law of conservation of mass! So I'm trying to figure out what it actually does, because obviously it works so there has to be an explanation."

The four boys stared at the Doctor with awe.

"Blimey," one of the twins said. "You're like a genius! Anyway, we're Fred and George Weasley. And Ron's our brother."

"I'm John Smith but call me the Doctor." The Doctor said.

"Isn't that a muggle Healer?" The twin on the right side said.

"Sort of."

"Okay. Well, see you around, John, Harry." They left, sliding the compartment door shut behind them. As soon as they left Ron turned to Harry.

"Are you really Harry Potter then?"

Harry nodded.

"Oh — well, I thought it might be one of Fred and George's jokes," said Ron. " And have you really got — you know…"

He pointed to Harry's forehead. Harry pulled back his bangs to show a peculiar lightning shaped scar. The Doctor whipped out his sonic screwdriver and brought it up to the scar.

"Ooh, now that is fascinating! There's a bunch of psychic energy concentrated around this scar. How did you get it?"

"Oh come off it, you don't know who Harry Potter is?" Ron asked. Harry looked extremely uncomfortable. "And what is that thing?"

"Screwdriver. And no, I don't."

"His parents were killed by You-Know-Who but Harry survived."

"You-Know-Who, is that Grindelwald or Voldemort or—"

But he didn't finish because Ron cut him off. "You said You-Know-Who's name!"

"Wait, which one is he? I get confused. For some reason lots of dark lords get called that. Never understood it. Names are powerful. By calling him You-Know-Who you're giving away that power!"

"It was Voldemort," Harry said quietly. "And I'd rather not talk about it anymore."

They quieted down.

"Are all your family wizards?" Harry asked Ron after a while.

"Er — Yes, I think so," said Ron. "I think Mom's got a second cousin who's an accountant, but we never talk about him."

"So you must know a lot of magic already." Harry said.

"I heard you went to live with Muggles," said Ron. "What are they like?"

"Horrible — well, not all of them. My aunt and uncle and cousin are, though. What about you John?"

"My family's gone." The Doctor said quietly.

"Oh, sorry," Harry stammered. "How, I mean how did they…" He trailed off.

"Oh, well, that's not important. Who wants to hear about boring old me. How many brothers do you have Ron?"

"Five," said Ron. He looked annoyed. "I'm the sixth in our family to go to Hogwarts. You could say I've got a lot to live up to. Bill and Charlie have already left — Bill was head boy and Charlie was captain of Quidditch. Now Percy's a prefect. Fred and George mess around a lot, but they still get really good marks and everyone thinks they're really funny. Everyone expects me to do as well as the others, but if I do, it's no big deal, because they did it first. You never get anything new, either, with five brothers. I've got Bill's old robes, Charlie's old wand, and Percy's old rat."

Ron pulled out a fat gray rat from inside his robes. It seemed to be asleep.

"His name's Scabbers and he's useless, he hardly ever wakes up. Percy got an owl from my dad for being made a prefect, but they couldn't aff— I mean, I got Scabbers instead." Ron blushed.

"Oh money, never had any." The Doctor said. "Why bother. Money makes you greedy. It makes you stop appreciating the beauty of the universe. It's usually the people without money who live the most fulfilling lives."

"I've never had any money before I found out about magic. I didn't know anything about being a wizard or my parents or Voldemort," At this Ron winced. "Until Hagrid told me," said Harry. "I bet I'm the worst in the class."

"Rubbish! We're all basically starting at the same level. It really doesn't matter how you were brought up. Pure-bloods just like to think it does." The Doctor interjected.

Harry looked happier at this. They lapsed into a comfortable silence.

At half past twelve the door of the compartment opened again to reveal a smiling woman with a cart.

"Anything off the cart, dears?"

She asked. Harry leapt up and proceed to buy a bit of everything while Ron turned red and muttered something about a sandwich. The Doctor continued reading. He was re-reading some of the passages for what seemed to be the thousandth time, trying to understand the theory of Transfiguration. It was really bothering him.

Harry came back in with an armful of candy and dumped it all onto the last empty seat. He invited Ron and The Doctor to take some. Ron grabbed some and stuffed it into his mouth while the Doctor declined. He wasn't feeling hungry.

Some time later the door slid open again. It seemed like everyone wanted to interrupt them. A round faced boy stuck his head into the compartment.

"Sorry," he said, "but have you seen a toad at all?"

They shook their heads and he wailed, "I've lost him! He keeps getting away from me!"

"What's his name?" The Doctor asked.

"Trevor."

"Well, when you find him you should ask him why he left. Maybe he was trying to find something. Just tell him that you were worried and to come back in an hour next time."

Everyone stared at him as though he was crazy.

"I've got to go look for Trevor. If you see him…" The round faced boy said and left.

"Don't know why he's so bothered," said Ron. "If I'd brought a toad I'd lose it as quick as I could. Mind you, I brought Scabbers, so I can't talk."

The rat was still sleeping. There was something a bit off about him.

"He might have died and you wouldn't know the difference," said Ron in disgust. "I tried to turn him yellow yesterday to make him more interesting, but the spell didn't work. I'll show you, look..."

He took out an old and very battered wand that seemed as if it was about to snap. "Unicorn hair's nearly poking out. Anyway,"

He raised his wand jus as the door opened for the fifth time and a girl with curly hair walked in along with the boy who lost the toad.

"Has anyone seen a toad? Neville's lost one," she said.

"We've already told him we haven't seen it," said Ron, sounding annoyed. The girl however was looking at his wand.

"Oh, are you doing magic? Let's see it, then."

She sat down in the last empty seat. Ron looked taken aback.

"Er — alright. Sunshine, daisies, butter mellow, Turn this stupid, fat rat yellow." Nothing happened.

"Hmm, let me try." The Doctor pulled out his wand and pointed it at Scabbers. He knew that magic was just psionic energy. Concentrate hard enough and you don't even need a wand. The wand and the words were like shortcuts. But even without them it was possible.

The Doctor concentrated very hard on the color yellow, picturing the rat in that color. He gave the wand a short jerk and said, "Fiet Flavo"

The rat turned a vibrant yellow.

"What is that spell?" The girl asked. "I've never heard of it."

"Oh, I made it up. 'Fiet Flavo' is 'become yellow' in Latin. Most of the spells are in Latin too. I suppose there's some link in the language that makes it easier than English. With enough concentration it would work in English as well. Look."

He lifted his wand again and concentrating on a sky blue this time said, "Turn Blue!" He jerked his wand as he said it and the rat turned the exact blue he was picturing. He smiled.

"Well, I've tried a few simple spells just for practice and it's all worked for me. Nobody in my family's magic at all, it was ever such a surprise when I got my letter, but I was ever so pleased, of course, I mean, it's the very best school of witchcraft there is, I've heard."

"Oh, Ilvermorny is a great school. Their sorting makes more sense though I still think splitting up students is a bad idea. Oh and Durmstrang produces some of the most powerful wizards. Shame that they get a bad reputation because of the Dark Arts."

"What are Ilvermorny and Durmstrang?" Harry asked.

"They're wizarding schools. Ilvermorny is in America and Durmstrang is somewhere in western Russia. But we don't know for sure."

"I've learned all our course books by heart, of course, I just hope it will be enough."

"Memorizing the books won't help you. Understanding them will. See, the difference between learning and memorising is understanding. Can you expand on the ideas of other people? Can you explain why something is that way? That's what learning is. Which is why I'm trying to figure out Transfiguration. It just doesn't make sense."

The girl looked stunned at this. She recovered quickly however.

"My name is Hermione Granger, by the way, who are you?"

"The Doctor."

"What kind of name is that?" Hermione asked.

"It's my nickname."

"Ron Weasley," said Ron, through the food he was chewing.

"Harry Potter."

"Are you really?" Hermione said, looking interested again, "I know all about you, of course — I got a few extra books for background reading, and you're in Modern Magical History and The Rise and Fall of the Dark Arts and Great Wizarding Events of the Twentieth Century.

"Am I?" Harry looked overwhelmed.

"Goodness, didn't you know, I'd have found out everything I could if it was me. Do any of you know what House you'll be in? I've been asking around, and I hope I'm in Gryffindor, it sounds by far the best; I hear Dumbledore himself was in it, but I suppose Ravenclaw wouldn't be too bad…"

"I honestly don't care. I think the sorting is all rubbish anyway. All it does is create unnecessary drama and tension between students," the Doctor said, still looking down at his book, "I could see myself going into any of them."

"Anyway, we'd better go and look for Neville's toad. You two had better change, you know, I expect we'll be there soon." Hermione said and left the compartment.

"Whatever house I'm in, I hope she's not in it," said Ron, throwing his wand into his trunk. "Stupid spell — George gave it to me, bet he knew it was a dud."

"Well, it really doesn't matter what you say as long as you concentrate on it. It's just the words and the motions help concentrate the energy. The more times the spell is done with certain words and motions, the more ingrained it gets in the psionic field and therefore it's easier to repeat. It's like a shortcut, the first person who goes through it has to create it, then it gets easier and easier. That's why some spells are easier to cast, they've been done more times."

"What house are your brothers in?" asked Harry, trying to cheer Ron up.

"Gryffindor," said Ron. Gloom seemed to be settling on him again. "Mom and Dad were in it, too. I don't know what they'll say if I'm not. I don't suppose Ravenclaw would be too bad, but imagine if they put me in Slytherin."

"Don't worry, it tends to run in the families. It's not a guarantee, but still, you don't strike me as a Slytherin. No offence but you don't seem sly or cunning. I'm thinking you'll be in Gryffindor or Hufflepuff. Anyway, what do you have against Slytherin?"

"That's the house Vol—, I mean, You-Know-Who was in, right?" Harry asked.

"Yeah," said Ron. "Everyone knows Slytherins are all evil."

"Well that's rubbish. There are plenty good wizards from Slytherin. Merlin was one, so was Horace Slughorn. Every house has some bad apples, doesn't mean everyone is like that. Don't make assumptions and get to know the person. They might be completely different from what you originally thought."

"Yeah, I mean my Uncle and Aunt thought that all magic was bad and I got treated horribly because of that. If they didn't think that maybe everything would be different. I'm not going to make assumptions like that." Harry said.

"I guess that's true. I still don't want to be in Slytherin." Ron said frowning.

"So what do your oldest brothers do now that they've left, anyway?" Harry said, trying to get Ron out of his bad mood. He was also wondering what a wizard did once he'd finished school.

"Charlie's in Romania studying dragons, and Bill's in Africa doing something for Gringotts," said Ron. "Did you hear about Gringotts? It's been all over the Daily Prophet, but I don't suppose you get that with the Muggles — someone tried to rob a high security vault."

"Really," the Doctor said, interested again. "What happened?"
"Well that's the thing, they weren't caught. They haven't been caught. My dad says it must've been a powerful Dark wizard to get round Gringotts, but they don't think they took anything, that's what's odd. 'Course, everyone gets scared when something like this happens in case You-Know-Who's behind it."

"What's your Quidditch team?" Ron asked.

"Er — I don't know any," Harry said looking embarrassed.

"Me neither, what is Quidditch?" The Doctor asked.

"What!" Ron looked almost offended that they didn't know. "Oh, you wait, it's the best game in the world—"

He started telling them all about the game. He was still talking when the compartment door slid open again. The Doctor started wondering if the door had a sign that said "Open the Door, we want to be interrupted!" on it. Three boys entered, and the blond boy in the middle, who seemed to be the leader asked, "Is it true then? They're saying all down the train that Harry Potter's in this compartment. So it's you, is it?"

"Yes." Harry answered, staring at the other two boys.

"Oh, this is Crabbe and this is Goyle," said the blond boy, looking bored. "And my name's Malfoy, Draco Malfoy"

"Hello, Crabbe, Goyle. Do you guys have first names or do you prefer being called by your last names?" The Doctor asked.

"I'm Vincent and he's Gregory." Vincent Crabbe said.

"It's very nice to meet you guys." He held out a hand first to Vincent, then to Gregory, and lastly to Draco.

Both Vincent and Gregory shook his hand but Draco looked at it like it was a piece of dirt. "And you are?"

"The Doctor."

"That's a muggle title." Draco said.

"Yes, it's my nickname."

"You must be a mud-blood then."

"Does it matter?"

"Of course it does."

"Why does it matter?"

"Because pure-bloods are better than mud-bloods!" It was clear that Draco was getting frustrated.

"Oaky, then how are they better?"

"I don't know! They just are!" Draco was getting really upset. "Anyway it doesn't matter," He turned back to Harry. "You'll soon find out some wizarding families are much better than others, Potter. You don't want to go making friends with the wrong sort. Like him," He turned to Ron. "He's a Weasley. My father told me all the Weasleys have red hair, freckles, and more children than they can afford. Anyway, I can help you." He held out a hand to shake.

"You know, I think the Doctor's right. Can you explain why you think you're better than Ron?"

Draco looked angry again. He was about to retort when the Doctor said, "What about you Gregory? Do you think you're better than other people?"

The boy looked surprised that the Doctor had asked him but after a few moments said, "No, I don't see why I would be. My dad always told me that pure-bloods were the best and that muggles were scum but he never explained it. I don't know why we would be."

"And you, Vincent?" The Doctor asked turning to the other boy.

"I guess I agree with Greg, now that I think about it."

"Good, good, you're thinking for yourselves. You're no blindly following whatever you're told. That makes you really smart."

Both boys were taken aback. They looked as though this was the first time anyone had told them they were smart.

"Whatever. Let's go." Draco said, his cheeks tinged a pale pink.

"Bye Vincent, bye Gregory." The Doctor called to them and they waved back.

He had just sat down again when the compartment door opened for the seventh time. The Doctor closed his book, the universe seemed to want to distract him today. Hermione poked her head inside and said, "I heard raised voices, is everything okay?"

"Yeah, we've just met a few new people." The Doctor answered.

"Vincent and gregory seemed okay, but Malfoy is a jerk."

"You've met Malfoy before?"

Harry explained to them about his encounter with Draco when he went to get robes in Diagon Alley.

"I've heard of his family," Ron said. "They were some of the first to come back to our side after You-Know-Who disappeared. Said they'd been bewitched. My dad doesn't believe it. He says Malfoy's father didn't need an excuse to go over to the Dark Side." He turned to Hermione. "Can we help you with something?"

"You'd better hurry up and put your robes on, I've just been up to the front to ask the conductor, and he says we're nearly there."

"Thank you Hermione. We'll do that now."

"All right — I only came in here because people outside are behaving very childishly, racing up and down the corridors," Hermione said in a sniffy voice. "And you've got dirt on your nose, by the way, did you know?"

Ron blushed again and attempted to wipe the dirt off his nose. Outside it was getting dark, the reds and oranges of the sunset fading into the black trees. The three boys changed into their robes and sat back down. The Doctor noted that Ron's were a bit short.

"We will be reaching Hogwarts in five minutes' time. Please leave your luggage on the train, it will be taken to the school separately." A voice called out through the train.

Harry and Ron both looked very nervous but the Doctor was having the time of his life. He had put away his book, though he still didn't completely understand how Transfiguration worked. Finally the train stopped and all the kids filed out. It was a bit cold and to his right the Doctor saw Harry shiver.

Then a light came from somewhere accompanied by a booming voice. "Firs' years! Firs' years over here! All right there, Harry?"

The Doctor looked up at a giant man with friendly black eyes.

"C'mon, follow me — any more firs' years? Mind yer step, now! Firs' years follow me!" He called again. All the first years followed the giant man who led them down a slippery, narrow path, surrounded by dark trees.

"Ye' all get yer firs' sight o' Hogwarts in a sec," The man called over his shoulder, "jus' round this bend here."

As they turned the bend the was a collective "oooh" from the students. The Doctor had to admit that the castle looked ethereal, perched on a high mountain overlooking the giant lake, set against the starry sky.

"No more'n four to a boat!" The giant called and pointing to the little boats by the shore. The Doctor clambering into one with Harry, Ron, and Hermione.

"Everyone in?" shouted the giant man, sitting in a boat by himself. "Right then FORWARD!"

All of the boats glided forward over the smooth surface of the lake. As they approached the first cliff the man, he really should learn his name, called, "Heads Down!"

Everyone ducked their heads as they passed under the cliff. They traveled through some ivy and down a dark tunnel until they reached a harbor underground and clambered out.

The giant checked the boats and called out. "Oy, you there! Is this your toad?"

"Trevor!" yelled Neville, and held out his hands.

They climbed up, following the lamp, walked up a flight of stone steps, and crowded around the huge, oak front door.

"Everyone here? You there, still got yer toad?" The giant asked. Neville nodded. The man raised his hand and knocked on the wooden door three times.

A/N: So tell me, do you like it? It's going to be different now that it takes place in the first book. However I think this will make it better. Also I think in the book Crabbe and Goyle were written as extremely stupid and just there to follow Malfoy around. So why were they in Slytherin? So I'm gonna change their characters to make them better. So they're not the brightest but they're not idiots.