So what if, instead of landing in Amy's backyard, The newly regenerated Eleventh Doctor crash landed in Hogwarts during Harry Potter and the Chamber of Secrets? Well, enjoy! Also, this contains dialogue from the Chamber of Secrets.

(From The End of Time, Part Two)

[The Tenth Doctor regenerates, the energy blowing out the windows of the TARDIS and setting the console room ablaze. The Eleventh Doctor screams in pain as he emerges.]

The Doctor: Legs! I've still got legs. [Kisses one of them.] Good. Arms, hands. Ooh, fingers. Lots of fingers. Ears? Yes. Eyes: two. Nose... eh, I've had worse. Chin - blimey! Hair... [notes length.] I'm a girl! [Checks Adam's apple.] No! No! I'm not a girl! [pulls a lock of his hair in front of his eyes and looks at it, agitated] And still not ginger! There's something else. Something... important, I'm... [taps head.] I'm-I'm...

[The whole console room shakes.]

The Doctor: [ecstatic.] Ha-ha! Crashing!

[As the burning TARDIS falls to Earth, the new Doctor clings to the central control column, laughing and whooping with glee. He looks up and shouts]

The Doctor: Geronimo!

Doctor Who / Harry Potter: Harry and The Doctor

Chapter One: Spectacular Entrance

Hogwarts, the Quidditch Pitch

"Oh look," said Flint. "A Pitch Invasion."

Ron and Hermione were crossing the grass to see what was going on. "What's happening?" Ron asked Harry. "Why aren't you playing? And what's He doing here?"

He was looking at Malfoy, taking in his Slytherin Quidditch robes when, there was a loud crash. Well, a loud sound that almost certainly could have been a crash. Everyone, including the entire Slytherin and Gryffindor Quidditch teams winced, turning to see this new arrival.

It was a blue box, an upturned blue box, with smoke billowing out of it. Then, a massive rope was flung to the feet of the Quidditch teams, and next; a hand appeared on one ledge. Then another, and finally, a head popped up, soaking wet and enthusiastic. "Can I have an apple? I love Apples! All I can think about, Apples! Maybe I'm having a craving! That's new, Never had cravings before."

Then, the stranger climbed up, and sat on the threshold of the blue box, looking down. "Whoo! Look at that!"

Everyone edged closer. "Uh, are you alright?" Ron broke the silence.

"Just had a fall, all the way back down there right to the library. Hell of a climb back up."

"You're soaking wet," added Hermione.

"I was in the Swimming Pool," smiled the stranger.

"You said you were in the library."

"So was the swimming Pool," replied the stranger, smiling at them all.

"Are you a policeman?" asked Harry. "Like the Muggle Policemen?"

"Why?" asked the stranger. "Did you call a policeman?"

"No," Ron remarked.

"Oh good then, I'll be – Argh!" The stranger stopped and fell off the box onto the floor, withering in pain.

"Are you alright?" Ron repeated.

"No, I'm fine," the stranger smiled, lifting a hand back up from his crouching position. "This is all perfectly normal. Suddenly, he breathed, and coming out of his mouth was a yellow light, curling.

"Who are you?" asked Malfoy. "How'd you get here?"

"I don't know yet," replied the stranger, the same yellow light appearing on his hands. Now, everybody was shocked. "Still cooking."

The yellow light vanished, and the stranger climbed to his feet. "Now then. I'm The Doctor. Could someone please tell me where the hell I am?"

He looked at the three Quidditch goals, and then turned around. He walked up to Harry and looked at him. By now, he was surrounded by both Quidditch teams. There was a moment of silence.

"Oh, oh you can't be!" The Doctor exclaimed enthusiastically. "Hel-llo Hogwarts! I hit the jackpot, newly regenerated, kaboom! Best post-regeneration landing ever!"

"Regeneration?" asked Hermione, confused.

"Hey, Harry," whispered Ron under his breath. "I think he may just be crazy."

"Anyway, what year are you all in? Not seven, defiantly not. No; not Three, That's it! You're Second Years! That means you've still got the... ah, bit to come. Probably shouldn't have mentioned that."

"How do you know so much about us?" asked Fred.

"Yeah? How come you know what year Harry and Ron are in?" George added.

"It's a long story," remarked The Doctor. "Well, come to think about it, at the moment, two books."

"Two books? Whatddya mean?" asked Ron.

"Strictly confidential," replied The Doctor.

And then there was a scream.

"Oh!" The Doctor shouted. "Now that's more like it, or rather not more like it! Come on then, let's find out who that person is and why that person is screaming. Geronimo!"

The Doctor took off, followed by a slightly bemused Gryffindor Quidditch Team, along with, reluctantly, the Slytherins.