Chapter One

"Any homework tonight, Hermione?" asked Ron as the trio sat in the Gryffindor Common Room that wintry evening in November. The Common Room was empty except for them, as everyone else was having an early night after a sleeping gas set off by a Slytherin entered the Tower. Harry and Ron had been in the Library, helping Hermione find books for some "light reading".

"Yes, we have that Charms essay on the Summoning Charm to do, that Potions recipe to memorise for the test tomorrow, and we have to practise turning badgers into magpies for Transfiguration," recited Hermione, as though all this homework would be no trouble.

"Oh great," said Harry sarcastically. "They should give us more time to do homework!"

"Harry, you've had a week to complete the homework!" scolded Hermione. "I completed the Charms essay on Tuesday, and I know the Potions recipe anyway, all I have to do is practise my Transfiguration. I haven't quite perfected the spell; the magpies never have beaks…"

"Hermione, how can you be so bloody brilliant at homework?" asked Ron.

"Because, Ronald, I try."

"What's that noise?" said Harry suddenly, interrupting their bickering. The three of them fell silent; a whirring, mechanical noise was becoming louder, and something large began to materialise to their right…

"A…police box?" said Hermione in disbelief, leaping up from the sofa as the whirring noise stopped. A blue, 1950s police box was sitting in the middle of the Gryffindor Common Room, having just appeared out of thin air.

"A please-box? What's one of them?" asked Ron bemusedly.

"A police box is what the public used in the 1950s to call the Muggle police, but they've almost all been taken off the streets. But I don't understand how one just materialised here, even if it's a magic police box…you can't Apparate inside the Hogwarts grounds, remember?"

Suddenly, the door to the police box swung open, and out stepped a young man wearing a long, brown coat, a brown shirt and pinstriped trousers, and a young, blonde woman, who were looking around the Common Room in interest, not noticing the trio.

"Where are we, Doctor?" asked the blonde woman.

"This, Rose, is Hogwarts School of Witchcraft and Wizardry, in Scotland," the man replied. "Been here before once when a bunch of Slitheen tried to invade, ooh, about 20 years ago now?"

"Witchcraft and Wizardry?" said Rose, raising an eyebrow. "You're pulling my leg, Doctor."

"Rose, you've travelled with me long enough to know that anything is possible," said the Doctor indifferently.

"Who are you?" demanded Harry, drawing his wand and pointing it directly at the Doctor. The Doctor and Rose spun around, finally noting their presence.

"Oh, hello there!" said the Doctor enthusiastically. "Didn't see you there! I'm the Doctor and this is my assistant, Rose Tyler."

"Doctor?" said Hermione sceptically.

"Don't you mean Healer?" asked Ron bemusedly.

"No, I assure you, I'm the Doctor. Now, I take it this is Gryffindor Tower…"

He pulled a short, metal stick from his pocket and began examining the Common Room, pointing it at the moving portraits and Remembralls.

"What are you doing?" asked Harry, confused.

"I wouldn't bother, he's a bit secretive," said Rose.

"I've noticed," said Harry. "Look, why are you here? How are you here? How did that police box Apparate inside the grounds?"

"That, my friend, is called the T.A.R.D.I.S., stands for Time and Relative Dimensions in Space. We didn't Apparate here, we travelled through time here," explained the Doctor.

The trio stared at him, waiting for more information.

"Well, that wasn't quite the reaction I was hoping for. Usually when I tell people the T.A.R.D.I.S. travels through time they're completely shocked!"

"Well, wizards can travel back in time as well," Hermione informed him.

"Yes, but the T.A.R.D.I.S. can travel backwards and forwards in time, and at a far greater range than your Time Turners can!"

"Look, how do you know about the Wizarding World?" demanded Ron.

"Ronald, don't you listen?" snapped Hermione. "They've been here before!"

"I've been here before," the Doctor corrected her. "This is Rose's first trip to Hogwarts!"

"So are you two…Muggles then?" asked Ron.

"Well, Rose is," the Doctor told them. "I, however, am a Time Lord from a planet trillions of miles away from your own galaxy. I travel the universe with my assistant, and help put a stop to evil along the way."

"You're an alien?" said Hermione in horror.

"If that's what you have to call me, my dear, yes, I am an alien. Now, enough questioning of me, you lot haven't told me about yourselves!"

"How do we know we can trust you?" scathed Harry. "For all we know, you could be Death Eaters!"

"My friend, if I were a Death Eater then I would have attempted to kill you already, don't you think?" said the Doctor exasperatedly.

"Oh, right," said Harry. "I'm Harry Potter, and these are my friends, Ron Weasley and Hermione Granger."

"Pleasure to meet you all! Now, we have some business to do, so, if you don't mind, we're going to see the headmaster, so, goodbye for now!"

"Wait, what about the…T.A.R.D.I.S.?" asked Hermione. "You can't just leave it here! When everyone gets up tomorrow-"

"I assure you, it will be gone by then, so, you don't have to worry you're little heads off! Goodbye!"

The Doctor and Rose looked around for a way out of the Common Room, but there apparently wasn't one.

"Erm, how do we get out of here?" asked Rose.

"Just push the portrait in front of that hole open," said Ron, pointing to the portrait hole.

"Thanks!" said the Doctor cheerfully, following Ron's instructions and climbing through the portrait hole with Rose. As the portrait swung shut, the trio turned to look at each other.

"What was that about?" asked Harry

"And what business does he have with Dumbledore?" said Hermione, frowning.

"Time travellers?" said Ron in excitement. "Now, we've got to check out this Tardy thing or whatever it's called!"

He rammed the door of the T.A.R.D.I.S. several times, before stepping away and rubbing his shoulder.

"It's impossible!" he cried. "It didn't even budge! Not even by a millimetre!"

"Ron, how are you shocked by this thing?" asked Hermione, laughing. "There are things like this all over the Wizarding world!"

"Yes, but still…there's something about this T.A.R.D.I.S…."