In Which the TARDIS Happens
"You're going to love this," the Doctor exclaimed. "White sand, pink water and three suns - anyone who doesn't like this planet is either insane or visually impaired."
"Sounds like fun," Rose grinned, taking the Doctor's arm and looping hers through it.
"Allons-y!" the Doctor grinned, before opening the doors.
A hall full of children stared back.
"Oh my God," Rose whispered. "Are we where I think we are?"
"What?" the Doctor asked, surprised. "Do you know where we are? Because I honestly have no idea."
"Have you ever read the Harry Potter series?" Rose asked, slightly out of breath.
"Always meant to, never did," he replied.
"We are in it," she said. "We are actually in Harry Potter, in Hogwarts, in the Great Hall."
"The wot now?" the Doctor asked, taken aback.
"Oh God," Rose turned to look at the Doctor. "The second we get back to the Tardis we're going to buy all the seven books."
"I'm sure I have some of them in the library," the Doctor muttered, turning around.
"Wait, where are you going?" Rose asked, alarmed.
"What are you waiting for?" the Doctor's voice rang from somewhere in the TARDIS, followed by a curse and a muffled, "Where the hell is that library?"
"Doctor!" Rose followed him quickly.
The shocked humans in the Great Hall stared in shock as the box vworp-vworp-vworped away, leaving only silence and a few shattered plates on the Gryffindor table behind.
The silence was disturbed as Quirrell burst through the doors.
"Troll! In the dungeons!"
"Oh dear," Dumbledore muttered, standing up to calm the children.