In the year 6038, on a small planet somewhere outside the Whirlpool galaxy, there stood a 1960s British Police Public Call Box. It had no business being on this small planet, but that had never stopped it before, nor would it likely stop it anytime in the future. Few noticed it, and fewer still bothered it at all. If someone did notice it at all, they got the feeling that it was waiting for something. Or perhaps someone.
The TARDIS (Time And Relative Dimensions In Space) was indeed waiting for someone. She was, in fact, actually waiting for two people, though not at the same time. Time was relative for a semi-sentient ship that could travel through time and space.
The Doctor, her Doctor, was off on an adventure at the moment. She didn't expect him back for some time. So, for the moment at least, she was sitting around, idly twiddling her metaphorical thumbs. He'd be here soon, her other adventurer.
What seemed like minutes, but could have been hours or even days (time goes a bit fuzzy when you can see all of what was, what will be, and what could have been all at once), he arrived in a hale of bullets. It was just like him, she supposed. Always moving, never still, leaving and arriving in the flashiest manner possible. She put up her barrier (invisible, of course, can't let the enemies know about that little trick) as soon as he was close enough to be protected by it. She cloaked him, hid him from their sensors. Eventually, they gave up, grumbling and going back to wherever it was they came from.
He waited a few extra minutes (smart boy, you could never be too careful when you were being chased by Ruolani bounty hunters), then came around to look at her properly. "Aren't you a pretty thing," he crooned.
Her circuits heated. The Doctor loved her, she knew, but sometimes he didn't tell her as often as she thought he should. It was always nice being complimented.
"Who in their right mind would leave you out here in the open, where some deviant could come along and have their way with you?" He asked, running his hands gently along her side.
Well, with a compliment like that, who could possibly refuse? She shook a little, dislodging the spare key from above the doorframe (really, Doctor? A spare key on the doorframe? She really had to remember to have a word with him about that later). He bent down to retrieve it, the little golden key glistening in his hand. "Lock, meet key," he murmured, sliding the key into the lock and twisting. The door swung open easily.
He stepped inside, and his eyes widened as he took in the interior. A grin split across his face. "You and I," Captain Jack Harkness said, "are gonna have so much fun together."
The TARDIS whirred approvingly. Why not go have some fun together? She certainly wasn't too old to go off on a few more adventures. She lit up the levers and gears needed to start the travel protocols. Jack's eyes tracked the lights, and he flipped the switches, turned the gears, pulled the levers. "Let's go for a ride," he said, and punched the ignition.