vworrrrrrrrp... vworrrrrrrrrp...vworrrrrrrrrrp
Deep in the Appaloosan Desert, a blue police box that was most certainly not an outhouse faded into view. The door opened, and Twilight stepped out, alone.
The door swung shut behind her.
Twilight looked out at the sand, more sand, and a single hardy cactus, growing almost right next to where the TARDIS had landed. There was no sign of anypony for miles around. She took a deep breath. “DISCOOOOOORD!”
“Alright, alright, there's no need to shout, I'm right here,” said the cactus.
Twilight turned and stared as the cactus unfolded mismatched limbs, quickly transforming into a familiar draconequus.
“And might I say,” added Discord, “you're looking particularly sooty today. It's an interesting new look, I'll grant you that, but it just needs a certain je ne sais quoi... no, wait, I do know what.” Discord reached behind his back and pulled out a flower, which he tucked neatly behind Twilight's ear. “There,” he said, conjuring up a mirror so Twilight could see her reflection. “Much better, don't you think?”
Twilight sighed, and closed her eyes. “Thank you, Discord, but my appearance is hardly a major concern at the moment. I do have a few questions, if you don't mind.”
“Oh, not in the least, not in the least,” said Discord. “The first three answers, in order, are of course I do, your diary, and of course, Princess.”
Twilight glared at him.
“Oh, my apologies, should I have waited for you to ask the questions first?” said Discord, grinning widely.
“Do you remember what you did to my friends in the maze, turning them grey and inverting their personalities?” she asked.
Discord smiled. Twilight stared at him.
“Surely I don't need to repeat myself?” asked Discord.
“Where did you get that list of answers from anyway?” asked Twilight.
Discord raised an eyebrow.
“But I don't keep a diary!” objected Twilight.
“You had better start one then, hadn't you?” Discord asked, his smile slowly widening.
Twilight glared at him.
“If you didn't want me to read it,” Discord finally said, “then why did you hide it in a triple-locked lead safe in the basement of Town Hall in a disused lavatory with a sign on the door saying 'Beware of the Leopard'?”
Twilight sighed. “Alright, we'll worry about the diary later,” she said. “Now, could you please not answer my questions before I ask them? It's really confusing.”
Discord grinned. “Of course, Princess,” he said.
“Okay, good.”
“Of course,” continued Discord, “this whole business of time travel is just full of confusion, isn't it? It's a pity I'm immune.”
Twilight blinked. “Immune?” she asked.
“Why, didn't the good Doctor mention it?” asked Discord. “As the amazingly handsome and absolutely perfect avatar of Chaos, I'm a fundamental force of the universe. Fundamental forces of the universe can't travel through time. Why, it's one of the few things that I have in common with your dreadfully tacky Elements of Harmony; if either of us were in that TARDIS and you left, you'd just leave us behind.”
“But, I've time-travelled,” objected Twilight. “And I'm the -”
Discord shook his head. “No, no, no, no, no,” he said, firmly. “You were the Bearer of the Element of Magic. You were never the Element itself. And you gave up even that much when you put your element back on the Tree. You are free to time travel to your hearts' desire, but your pointy little purple gem has to stay behind.” He drifted through the air, looping around to the other side of Twilight. “As one of the few things I can't do, I must say I've always been kind of fascinated by time travel,” he continued. “Did you know, I once tried to make a collection of Time Travellers? Before my reformation, of course. But why don't you introduce me to this Doctor of yours?”
“Oh! Right.” Twilight shook her head. “Before we do that, Discord, I want to ask you to promise me something.”
“Ohhhhhh,” said Discord. “I'd almost forgotten about that. Didn't you have some other questions first?” He raised an eyebrow. “Your diary was quite detailed about what you'd planned for this meeting, you know.”
Twilight nodded. “You turned my friends grey,” she said. “Have you ever – ever – done that to anypony else?”
“Of course not,” snorted Discord. “Chaos is all about not repeating yourself. Doing new stuff, not old stuff.”
“Okay, then,” said Twilight. “Could I ask you to Pinkie Promise not to do that to anypony at all for, say, the next hour?”
Discord shrugged. “Sure,” he said. “Cross my heart, hope to fly, stick a cupcake in my eye.”
There was a squelch as the cupcake, appearing out of nowhere in his eagle claw, hit him in the eye. Twilight winced, but Discord didn't appear to be in any discomfort. She reached out one rear hoof and knocked on the TARDIS door.
It swung open, and the Doctor stepped out.
“Doctor,” said Twilight, introducing the two, “Discord. Discord, the Doctor.”
“Doctor who?” asked Discord, reclining back on the air.
“You were talking about the Doctor earlier,” said Twilight, ignoring Discord's question. “You've met him before?”
“Oh, yes,” said Discord. “Reasonable fellow. Bit gruff. No sense of humour, but he's done some amazing things. Really, amazing.”
“Have you ever met sompony who looks like him, only grey?”
“You mean Paradox?” asked Discord. “Oh, yes.” Discord shuddered. “Horrible fellow. Absolutely terrible.”
“Right, well -”
“Oh, now, wait a minute!” said Discord, suddenly sitting up. “You don't honestly think I turned the Doctor into that – that thing, do you?”
“Well, not yet, perhaps,” said Twilight. “But he is a time traveller, so -”
Discord snapped his talon. The Doctor gasped, and backed up a few steps.
“I hereby Pinkie Promise,” said Discord firmly, “that I have not and never will invert the Doctor's personality. Cross my heart, hope to fly, stick a cupcake in my eye.” This time, the cupcake squelched into his other eye, leaving both covered.
Discord snapped his talon again.
“There,” he said. “That should resolve that, at least.”
“You can't do that!” objected the Doctor.
“I just did,” grinned Discord. His eyes opened on the outside of the two cupcakes.
“What?” asked Twilight. “He promised never to invert you! Isn't that a good thing?”
“Not that!” said the Doctor. “I mean, yes, that is a good thing, but, he just created a fixed point in time!”
Twilight looked back and forth between the Doctor and Discord. “A what?” she asked.
“Oh, come now.” said Discord. “It's a perfectly sensible thing to do. If I didn't, then some grey-coated time traveller could try to change history to prevent me from ever making that promise, couldn't he? I made it, and I intend to keep it.” He leaned closer to whisper to the Doctor. “Paradox is a lot less fun than you are, anyway.”
“What's a fixed point in time?” asked Twilight.
“It's an event that has to happen,” explained the Doctor. “Something that you can't prevent without breaking time itself.”
“And in this case,” continued Discord, “the fixed point was me, having been reformed, making a particular Pinkie promise truthfully and with every intention of keeping it.”
“And you can't just create one of those!” continued the Doctor. “Not so quickly, at least!”
“I thought you said you were immune to time travel,” said Twilight.
“Oh, and I am!” insisted Discord. “But I didn't exactly travel through time to do that, did I?”
Twilight sighed. “Sometimes I think Discord does impossible things just to mess with people,” she told the Doctor.
“You said you'd met Paradox before?” asked the Doctor.
“Oh, yes,” said Discord. “About, oh, two hundred miles south of Baltimare, one thousand, three hundred years ago? More or less, I never really bothered to keep accurate dates at the time. It was before I was reformed, you see, so I had no reason to keep track of whether or not it was Tuesday.”
“What do Tuesdays have to do with -” began the Doctor.
“Oh, and talking of which,” said Discord, “it just happens to be a Tuesday today. Time for my weekly lunch with Fluttershy. Toodles!”
He snapped his talon, and vanished.
There was a long moment of silence. Twilight broke it first.
“Do you think that will be enough to stop Paradox?” she asked.
“Will he keep that promise?” asked the Doctor.
“I do believe he would,” said Twilight. “It was a Pinkie promise, after all.”
“In that case,” said the Doctor, “no, it won't be enough to stop Paradox.”
“But -” began Twilight.
“The only reason you're here, now, is because you met him,” pointed out the Doctor. “Remove him from history, and you've got no reason to ask Discord to make his fixed-point-in-time promise. And time can't let that happen.” He shook his head. “No,” he said, “it is now completely impossible to prevent Paradox from ever having existed at all. We're just going to have to track him down again, and... and figure something out.”
“Could you find out where he went when he left Canterlot?” asked Twilight.
The Doctor shook his head. “No,” he said. “That jump has too much interference. Paradox is hiding his tracks.”
“Then how can we find him?” asked Twilight.
“Well,” said the Doctor, “I do have one clue. Apparently he was about two hundred miles south of Baltimare, one thousand three hundred years ago...”