Disclaimer: I don't own Harry Potter or Doctor Who. I just had a fun idea to mix them together

"Ahhh!" The Doctor stepped out of the TARDIS, smoothing out his robes and motioning for Rose to come along. "Allons-y, Rose! Let's go!"

"Ummm…Doctor?" Rose looked down at her clothing. "What am I wearing?" She laughed.

"Wizard robes, Rose. Wizard robes!" Doctor grinned at her.

"Wizards? Are you joking?" She laughed.

The Doctor spun around to look at her for a moment, raising an eyebrow. "We've been all around the universe, Rose. You've seen thousands of species and aliens and all sorts of things you once thought unbelievable, and you choose to not believe in wizards? With all the tales that's been around from your people! The Salem Witch Trials for starters!"

"But they weren't really witches, Doctor…" Rose started.

"Oh weren't they?" The Doctor grinned. "Come along, then. I've got us both jobs at Hogwarts School of Witchcraft and Wizardry for now! Welcome to Hogsmeade!"

"Hog-what?" Rose stared at him. "But I don't know a thing about wizard-"

"That's why I've got you a job in muggle studies, dear Rose." The Doctor tapped her nose. "Muggles. That's what wizards call non-magic folk." He looked around. "We'll be undercover of course…" He walked around the shrieking shack, making sure the TARDIS was hidden from wizard eyes. "Come on then. We'll need to be careful. Dumbledore, an old friend of mine, he says he needs some help. We're to meet him before the feast in his office. Don't want to miss the feast! Hear it's great!"

"Doctor, you're insane!" Rose laughed as he pulled her along the Hogsmeade path up to the castle.

"Ahh, Doctor." Dumbledore greeted them as soon as they reached his office. "And you must be?" He looked to Rose over his half-moon spectacles.

"Rose, sir. Rose Tyler." Rose smiled, holding out her hand to shake. "It's great to meet you! Doctor's told me so much about the great things you've accomplished!" On the way up here… she added in her mind.

"Ah. It is our choices that show who we truly are, far more than our abilities, Miss Tyler." Dumbledore smiled kindly at her.

"Very wise, sir." Rose smiled. "And it's Rose."

"Then I must insist you call me Albus." Dumbledore chuckled, moving over to sit in his desk chair. "Please, sit." He gestured for The Doctor and Rose to sit in the chairs across his desk.

"Lovely office." Rose complimented, looking intrigued at all of the foreign objects around her.

"Thank you, Rose." Dumbledore smiled at her. "Unfortunately our greetings must come to an end." He sighed. "Doctor, I'm sure you remember the great wizarding war between death eaters and wizards alike?"

"Ahh, yes!" Doctor nodded. "Voldemort was a dark and powerful wizard." He explained to Rose. "He wanted all wizards and witches to be pureblood-only pure wizard, no muggle blood in the line. He believed those that were muggleborn- witches and wizards that were not born into magical families, but still have magical powers-were unworthy of learning and using magic. He caused terror for years and built an army of death eaters. Until one night on October 31, 1981, he went to the Potter's house. There was a prophecy saying that they're son, Harry, would defeat Voldemort. Anyone who faced Voldemort's wrath wouldn't live to tell a tale. The Potters were in hiding, trying to keep Harry safe. But their secret keeper, Sirius Black, gave them away…"

"Actually, Sirius Black is proven innocent in my book, Doctor. It was actually Peter Pettigrew that was the secret keeper." Dumbledore interrupted.

"Oh! Excellent! It tore me apart that Sirius would do such a thing! He's a great man! Anyway, Voldemort got into the house and killed James and Lily Potter, bless them. But when he got to baby Harry, he was just a year old at the time, he couldn't kill him. Voldemort disappeared that night, and Harry was left with only a scar on his forehead. No one knows how it happened, but it ended the war." The Doctor explained.

"Except, there have been signs of death eaters again, Doctor." Dumbledore handed him a copy of the Daily Prophet, the front page showing the events at the Quidditch World Cup-the dark mark symbol in the sky. "And I fear of Voldemort's return…soon."

"Those pictures move!" Rose pointed at the paper, completely in shock.

"Yes." Dumbledore chuckled light hardily despite the situation. "It's a magical way to develop them." He explained.

"Well then… Not to be rude, but I still don't see what you've brought me here for, Professor." Doctor handed the paper back over to him.

"Ah, events will unfold as they need to, Doctor. But I thought it would be best for an extra set of trustworthy eyes to be looking over young Harry this year." Dumbledore explained.

"Harry? Harry Potter?! Oh I can't wait to meet him!" The Doctor beamed, sitting on the edge of his seat.

"Yes, I'm afraid he's had quite a bit of that over the years." Dumbledore chuckled. "But as I was saying, Doctor. I've asked you and Rose here to go undercover as Professors. I'm going to ask you to take a polyjuice, Doctor, posing as auror Alastor Moody-or as some call him Mad Eye Moody. I may need you to go undercover as a death eater as well…" He said grimly. "But all in good time, Doctor. You should understand that."

"Right then." Doctor nodded. "I trust you completely. I'd be glad to do this for you. I do have one request though, that Rose and I have double quarters so we're right in the same living area."

"Of course, Doctor." Dumbledore nodded. "It's already ready for you. I'll show you where you'll be staying, teaching, and to your offices. I trust you know quite a bit about Defense Against the Dark Arts, Doctor? I'll be temporarily lending you some magic."

"Do I get any magic?" Rose asked curiously.

"I'm afraid not, Miss-excuse me, Rose." Dumbledore chuckled. "You being only muggle, it wouldn't work too well. Timelords seem to be able to absorb some magic here and there. Something to do with the regeneration process from what I understand." And with that, he showed them around the castle.

Author's Note: Hi there! I feel like this first chapter was a bit rushed, but I have a few surprises for later on in the fic. I've had this idea for a while but haven't had the time to get around to it. I'm sure this idea has been used 3454385 times, but I haven't actually read or written any Doctor Who fics! All have been purely Harry Potter. It's the tenth Doctor since David Tennant plays both the Doctor and Barty Crouch Jr.

I hope you enjoy it and follow and review! It would be fantastic! Thanks for reading! :)