Chapter 1

Disclaimer: Harry Potter belongs to JK Rowling. Doctor Who belongs to BBC.

"It's no good sitting there dreaming. No one's gonna come along with a magic wand and make your life all better." - Sylvia Noble (Partners in Crime)

It was a nice, quiet night in the TARDIS. It was one of those rare times when it was actually peaceful. There was nowhere to go. Everyone was safe. The Doctor savored his moment of relaxation, reading luxuriously in the control room.

The funny things about quiet moments in the TARDIS, however, was almost every time, they ended abruptly. A sudden jolt shook the entire police box to such a degree that the Doctor's book fell from his hands as he quickly found something - anything - to grab on to. He regained his balance by reaching out to one of the many cords that hung from the ceiling.

"Oi! Spaceman!" Donna yelled out into the control room, tugging on her bathrobe over her nightgown. "What would that be, then? Trying to rile me up when I'm trying to sleep?" she demanded.

"Wasn't me!" he insisted, bounding toward the center control. "It doesn't make much sense, what just happened. The Rexel system is practically empty! The planets here uninhabitable!"

"That's what you said about Midnight, innit?"

"That was different! The acidity in the air here would cut through steel. Not even the Daleks could sustain life in this galaxy." He explained, concentrating on the screen that sat in front of him. He tried a few things for a straight answer, even resorting to his sonic screwdriver, but to his disappointment, brought up nothing.

"I don't understand!" The doctor ran his hand through his bed hair. "How is this-"

Another great jolt shook through the TARDIS once again, throwing the doctor into Donna, pushing her to the ground.

"Get off me!" She demanded, pushing him with great force for a woman of her size. He immediately complied, sliding off her with impressive speed.

The doctor sprang to his feet as the time machine took off with its trademark whooshing sound.

"We're taking off!" The Doctor exclaimed with a tinge of confusion in his voice. "Where are we going?"

"Well, how am I supposed to know? You're the alien, not me!" Donna replied, her voice laced with sarcasm.

"I wasn't asking you." He responded.

"What? Am I supposed to believe that you actually talk to a machine?"

"The TARDIS is alive."

"What? Really?" She looked around the large room.

"Where are we?" The doctor muttered. He inched his way toward the door, and with Donna behind him, slowly and carefully eased the door open.

"What?" He cried. "Wha... What?"

Donna followed him out of the police box, completely shocked.

"Are we-" she trailed off.

"I think so." The doctor replied. He looked around, soaking up the sights that rushed over him. To his right stood a great castle at the base of a vast lake. It was evening, and the lights from the windows twinkled down over the grounds. To his left stood a fenced oval field with three hoops on each end that reached high into the sky. The TARDIS was shielded at the edge of the incredibly dense forest.

"Hogwarts castle." He stated with a tinge of glee.

"How in the bloody hell is this possible?" Is this really happening?" Donna laughed. "You never told me there really are wizards in England!"

"There aren't." He explained. "I think we're in the book. Look, try to focus on anything farther than 20 meters from you."

Donna squinted. Though everything close to her was clear as day, she couldn't focus on anything in the distance. It was almost as if she suddenly needed a prescription for nearsightedness.

"Well, that's annoying." She exclaimed. "What's causing that, then?"

"We're in the story. I expect the closer we get to the location of the plot, the clearer things will become. Like a bubble. The story is in the bubble, and if we stay inside, things are clear, but if we step outside, it'll get hazy."

"Oh, that clears things up then, doesn't it?" Donna stated, pointing to the horseless carriages that declared they were at the beginning of a year.

"Shall we go in?" The doctor asked, gesturing to the castle.

"Not dressed like this, I won't."

The doctor waited outside while Donna ran back into the TARDIS to get dressed. Some time later, she emerged in a simple green blouse and jeans. She'd fixed her hair in a ponytail.

"D'you think we'll be able to mess up the story?" Donna asked. "If we're in the book?"

"I don't think so, no. The story has already been told. As long as we do our best to stay out of the main story. You've read the books, you know which characters to stay away from."

"Like them." She pointed.

There they were. It was not at all like the movie had portrayed them, and Donna didn't really know what to expect, really. Ron was startlingly tall. Hermione was vastly less pretty. Harry's hair was sticking up all over the place. There was a fourth girl with them, short, with very long, shiny dark hair. The doctor and Donna quietly observed as they trotted away from the horseless carriages to the entrance of the castle.

"You fainted, Potter? Is Longbottom telling the truth? You actually fainted?"

The two travelers watched as Draco Malfoy elbowed Hermione as he rushed up the steps to the castle. He turned to block Harry's way, glee etched across his face.

"Shove off, Malfoy," they heard Ron respond to him.

"Did you faint as well, Weasley?" Malfoy called out loudly. "Did the scary old dementor frighten you too, Weasley?"

Donna looked up at the doctor, who was staring at the confrontation the characters were having with one another.

"Book three. We're in the third book. But why? Why now? I can't figure it out." The Doctor muttered

"I don't understand what you mean." Donna replied. "Why now? Does it matter what book we are in?"

"Yes," he whispered in reply. "Why not the first book? Something important happened near this part. That's why we're here." He continued observing.

They watched together as Hermione poked Ron in the back to get him to rush up the steps. The four students, Harry, Ron, Hermione, and the fourth girl the Doctor didn't recognize joined the vast amount of students flooding into the castle.

"Did you notice any difference between the book and now?"

"Dunno. I've only read them through the one time."

"How many main characters are there?"

"Three. Harry, Ron, and Hermione."

"There was a fourth this time." The Doctor said thoughtfully. "I think she's the one we need to talk to. She isn't in the book. She shouldn't exist, so why is she here?"