The reasons people became evil were varied and intricate. At least in theory. In reality, the Doctor had discovered that, 90% of the time, it was just some family issue. So, just pop back to the past, resolve some marital dispute, and bam! One less villain.
Which was why the Doctor and Derpy found themselves in front of Pinkie Pie's old rock farm a year before her birth. Or, more accurately, in front of Pinkie Pie's old rock farm whenever the TARDIS decided to dump them.
"Why don't we just go back to the hospital and prevent ourselves from blowing it up?" Derpy said.
"One, because that was all you," the Doctor said, "and two, what's the second rule of time travel?"
Derpy thought back. "Never seduce your parents?"
"No, but close. The other second one."
Derpy inhaled. She knew the one. It was hard to forget. "If you interfere with yourself interfering with time, giant space meatballs eat everything," she recited.
"Good."
"But," she said, "me making out myself apparently isn't a problem?"
"Time naturally works itself out if it's sexy," the Doctor said. "Now let's take a look around."
They started looking around the house, seeing if they could find any clues.
"You know, what exactly does a rock farm do?" the Doctor said, poking some termite eaten wood on the side of the house.
Derpy shrugged. "Farm rocks, I guess."
"Yeah, but you don't farm rocks. They're just there."
"What if you run out of rocks?"
The Doctor scoffed. "The whole planet is a giant rock. You can't run out of rocks."
"Yeah you can."
"What?"
"Well, what if a bunch of the natural processes got messed up or something?" Derpy said. "You'd have some rocks erode into dust, but there'd be no new ones to replace them, right?"
The Doctor looked back in horror. "I'm not sure where you learned geology, but a world would have to be pretty screwed up to reach anything even approaching that state."
The Doctor had reached the front of the house, and, desperate to end that conversation as quickly as possible, entered. Inside, as outside, it appeared to be completely deserted. Dust was beginning to gather on everything.
"Yeah," Derpy said, blowing some off her face, "looks like you went to the complete wrong time. Again."
"Not necessarily," the Doctor said, heading to the kitchen. He opened the fridge. "Look. This food's still good."
"Wait," Derpy said, "how does that make sense? The house is falling apart, there's week old dust, but the food's still good?"
"There's only one explanation." The Doctor looked around. "The occupants are still here." He started walking around the house. "Hello! Anyone here!?"
The surroundings were filled with that silence you only get with people trying to be quiet.
"Look around," the Doctor said. "They must be hiding somewhere. Maybe there's a hidden room."
Derpy nodded, turned around, walked away, tripped over a bump in the floor, hurtled into a cabinet, hit something inside, and triggered a secret passage. Part of the adjacent wall started rising up.
"Good job, Derpy!" the Doctor said, patting her on the back. "Your clumsiness has saved the day once again!"
"You're just being sarcastic."
"You think?"
They headed into the secret passage. After going down a couple flights of stairs, they reached a large, imposing, impractical looking metal door. It, among other things, lacked doorknobs. The Doctor pushed it open.
Inside was a small room. There was a table filled with a large assortment of equipment for mixing chemicals, a couch filled with a large assortment of equipment for things the Doctor could not describe without blushing, and, for some incomprehensible reason, a curtain. A bearded pony was at the table, deeply absorbed in trying to somehow combine the two sets of equipment.
"Oh," a bearded pony said. "Looks like you found the real business."
"You mean you don't farm rocks?"
"You seriously bought that?" the bearded pony said. "You can't farm rocks."
The Doctor smiled at Derpy.
"Who are you, anyways?"
"A time traveler." The Doctor decided to stroke his ego a bit. "The time traveler."
"Far out," the bearded pony said. "Hey, Mary! There's a time traveler here!"
A head that was presumably Mary's popped out from behind a curtain. "Just a sec!" she yelled. She returned behind it, and, after making some suspicious moaning sounds, emerged with her forelegs around two dumbly smiling stallions. She looked at the Doctor lustily. "You really do look like a time traveler," she tongued, because if anyone could tongue with thin air it was her.
"Um. Thanks?" the Doctor said, blushing. "Excuse me, just out of curiosity's sake… how do I look like a time traveler?"
"I can sense time particles on a person." She slinked around him slowly. "You're full of… time particles."
"Far out, man," the bearded pony said. They clopped their hooves together. It was like a high-five, except with no fingers and far, far more erotic.
Every part of Derpy save her wings looked disgusted. "I would just like to mention, for everyone's sake…" She put her hoof around the Doctor. "…he's mine."
"I am not," the Doctor, edging away from her. "More importantly, who are you two? We're kind of looking for some people."
The bearded pony cleared his throat. "This is Mary Jane Pie, I'm Ecstasy Pie, and these two are…" He looked at Mary.
"My sex slaves."
"Her sex slaves."
The Doctor stared at them.
Ecstasy smiled. "We are completely normal for this time period."
"No you aren't," the Doctor said.
"What? Everyone knows straights are promiscuous."
"I think that's just anti-straight propaganda," Derpy said.
Ecstasy fell silent, as if he was rethinking his entire life. "Well," he said, "that changes things."
The mood became awkward. The sex slaves continued smiling stupidly.
The Doctor made a mental note to never become a sex slave.
Derpy scrunched her face up in horror and leaned over to the Doctor. "You don't think…?"
"I just had the most radical idea," Ecstasy said. "Let's name our children after the ghosts in Pac-Mare."
"Sounds good to me," Mary purred. "Just picture it! Inkie Pie. Blinkie Pie. Pinkie Pie!"
The Doctor leaned back. "They are."
"Oh, oh!" Ecstasy said. "And we should pretend to be really fundamentalist through their entire childhood!"
"Their entire childhood!?" Mary looked at her sex slaves. "I don't know if I can handle that."
"Just think of it," Ecstasy said. "What's the best way to make sure they come out like us?"
Mary thought about it. "Rebellion."
"Exactly."
Mary looked excited, in more ways than one. "It's perfect!"
They started making out.
This time Derpy actually was completely disgusted. "These two are going to raise children?"
"Explains a lot, actually." The Doctor cleared his throat loudly, attracting Ecstasy and Mary's attention. "Anyways, I have something important to talk to you two about."
"What about?"
"Your daughter is going to become a serial killer. I'm here to stop that."
"Totally radical," Ecstasy said, nodding.
"No, it's really not," the Doctor said. "For one, she becomes a serial killer because you two die."
"Oh."
Mary pressed herself against Ecstasy. "How? Do we die in…" She licked the air. "…the heat of passion?"
"No, just a fire started by an incompetent, stupid nurse." The Doctor meaningfully glanced at Derpy.
Derpy glared back.
"So," the Doctor said, "when you have your first daughter, don't go to the Ponyville hospital."
There was an awkward pause.
"That's it?" Ecstasy said.
"That's it." The Doctor started to leave. "Now, before we overstay our—"
"No!" Mary ejaculated, grabbing him. "Stay a while. Please?" She stroked his inner thigh.
The Doctor's will slowly left him. "Oh, what the hell."
"We were just about to make some crystal meth," Ecstasy said. "Anyone want to give that a shot?"
Derpy raised her hoof. "Oh! Me! Me!"
– – – –
The house, now completely engulfed in flames, collapsed to the ground.
"I just don't know what went wrong," Derpy said, with slightly less conviction this time.
The Doctor glared at Derpy. "TARDIS. Now."
They went in the TARDIS. The Doctor traveled to some completely random time period, walked over to the door, and opened it. Outside was an overgrown looking forest. "Out."
"What?"
"Get out."
"What!?" Derpy approached the Doctor. "You're kicking me out!?"
"Yes. In 24 hours, you've killed an entire hospital's worth of people, and the parents and sex slaves of the person we were trying to save," the Doctor said. "You've turned an innocent pony into a serial killer and then erased her from existence." He glared. "I don't have many lines, but you've crossed nearly all of them."
"But it wasn't my fault!"
"If it wasn't your fault, then I'm a sparkly pony princess. Get out." He shoved her out of the front door.
"But you can't just leave me here! In the middle of nowhere! I'll starve!"
The Doctor looked at the grass and flowers that surrounded Derpy.
"Okay, I won't starve, but what if I don't find civilization!?"
"You'll manage."
The Doctor slammed the door shut and traveled away as quickly as possible. He leaned against the TARDIS control panel for a bit.
"You can relax now," the Doctor said. "She's gone."
The TARDIS seemed to sigh in relief.
"Sorry that took so long," he said, messing with some equipment, "I had to think of some pretext, otherwise it might have caught on."
He brought up the statistics again, just to be sure. The screen was full of numbers outside the realm of possibility. It described power levels far beyond anything the Doctor thought possible.
"Whatever that was," he said, "that definitely was not Derpy."
– – – –
"Dammit! Dammit! DAMMIT! DAMMIT!"
Derpy kicked a rock. It went through three trees and made a large gash in the canyon wall behind.
"I can't believe that bastard kicked me out!"
A small rabbit looked on in fear. Derpy walked over, crushed it with her hoof, and tore its head off with her teeth.
"Time to find out when I am."
Derpy removed her disguise and started her long walk home, wherever that was in this variation.
– – – –
After sending the fake Derpy away, the Doctor immediately went on sabbatical. He had actually been planning this for a while now, ever since the imposter first set foot into the TARDIS and all the power readings went into the quintuple digits. The Doctor originally planned to confront the creature, but after seeing those readings, he decided it would be safer for himself and the rest of the universe if he stayed in character and made them think their disguise was working. If those readings were accurate, they could have destroyed a significant part of the TARDIS if they breathed wrong. While he had yet to perfect his mental model of how the TARDIS and the universe connected, he had seen more than enough evidence that one exploding usually led to the other following.
So he immediately headed to the time period he had arbitrarily named the present and went to a café that had become a particular favorite for him. The scenery was great, the service tolerable, and, most importantly, little to nothing exciting ever happened there.
The Doctor ordered a sandwich, making it excruciatingly clear he didn't want meat on it, and leaned back in his chair. He relaxed for the first time in millennia.
Murphy's Law quickly came into effect.
"Hi!"
The voice was right next to the Doctor's head, but he figured they were talking to someone else.
"I'm not talking to someone else. I'm talking to you."
The Doctor whipped his head around.
Staring at him very closely, very intensely, was Pinkie Pie, the pony Derpy had supposedly erased from existence.
"Wha…?" he stammered. "Bu… you…"
"It's not that easy to erase me," Pinkie Pie said. "I must admit, I did prefer the last form, but the universe found a new way to incorporate me into this reality."
The Doctor was at a loss. "The… universe? But… we killed your parents! Before you were born!"
Pinkie Pie smiled. "You only need parents if you're alive, silly! Didn't I say I preferred the last form?"
The Doctor backed away, scared. "What… what are you?"
Pinkie Pie got even closer to his face. If he didn't know better, the Doctor would say she began to go through it. "Do you really want to know?"
"Yes."
"I'm cotton candy."
"What?"
"I'm the weapon."
"What?"
"I'm the universe's last effort to restore balance to creation."
Now the Doctor was completely confused. "…what?"
"I don't know how much more clearly I can explain it," Pinkie Pie said. "Now I have to go do this again in another timeline. Tootles!" She jumped into a nearby sandwich.
"Here you go," a waitress said, placing it on the Doctor's table. "One daisy sandwich."
"Did you see that!?" he said, sweating.
"See what?"
"Did you see that pony just jump into my sandwich!?"
The waitress stared at him.
The Doctor got irritated. "Tell me! Did you!?"
"Was she pink?"
"What?"
"She was pink, wasn't she?"
The Doctor wondered how that was relevant. "Yes. And?"
"That's Pinkie Pie," the waitress said, smiling. "She does that."
The Doctored gaped.
"Don't worry, it just makes the bread taste a little like strawberries. Enjoy your meal!" And she left to serve other customers.
The Doctor looked down at his sandwich, which was slightly pinker.
For some reason he didn't quite feel like eating it.
– – – –
Sprung into action by his violated sandwich, the Doctor decided to visit the one pony in this time period that probably knew what was going on.
Unfortunately, at the moment she wasn't being very cooperative.
"You have overdue library materials," Twilight said, glaring.
The Doctor groaned. "Look, can you please just tell me about Pink—"
"According to this," she said, producing a detailed looking checkout form, "you still haven't returned the books you checked out… three months ago." She looked back up at the Doctor. "You do realize what this means, don't you?"
The Doctor stared at her, blank.
"You have to pay a large fine. And return the books. Preferably both," she said. "Oh, and this."
"And wh—?"
Twilight grabbed the Doctor's head and slammed it into a nearby table.
"GAAAH!" the Doctor yelled, clutching his head. "What did you do that for!?"
"I've noticed that tends to help with punctuality. I learned it from Fluttershy. She really has been getting more assertive lately, don't you think? Ever since the humans… sorry, I'm getting off topic."
The Doctor had no idea who that was and wasn't about to ask.
"Well? What do you have to say for yourself?"
The Doctor had only tried this once before, and it was a disaster, but he wanted to end this as quickly as possible. "I'm a time traveler," he said, bracing himself. Her confusion would buy him enough time to run away, at least.
Fate had other ideas.
"I know."
The Doctor blinked. "What?"
"Why do you think I bashed your head in? You have no excuse for overdue books," Twilight said. "You could've had them back in an hour if you wanted. In fact, can't you just go back now and return them on time?"
"Um," the Doctor said, worried, "how did you know I was a time traveler?"
Twilight scoffed. "You just come out of nowhere, not knowing anything about this world or its history? What else would you be?" she said. "And I thought you looked familiar. I looked through the history books. You're everywhere."
The Doctor was not going to drop this. "How did you know I wasn't just, say… immortal?"
"Come on, don't be ridiculous. Only the princesses are immortal," Twilight said, prompting the Doctor to roll his eyes. "Besides, it's obvious from your behavior. What immortal would be confused about basic history in their own world? You'd have to be a hermit, which is extremely unlikely because you obviously still have enough social skills to get snippy." She glared at him. "Not to mention, you never tried to take power. What kind of self-respecting immortal doesn't try to seize power?"
The Doctor was about to object again when he realized it wasn't actually important whether she knew he was a time traveler. "Okay, we've gotten off-topic. I'll get you your books. Can you just tell me about Pinkie Pie?"
Twilight glared, but conceded. "Fine. When I first met her, I was also curious, so I asked around. Apparently she just sort of appeared out of nowhere one day. No one quite knows when, where, or how. All anyone can remember is it was the one time they saw her looking distraught. When someone asked her about it, she just said she came from 'home,' desperately needed to make cupcakes, and refused to say anything further." Twilight looked out the window. "Everyone has a different theory about her, none conclusive." She smiled. "Personally, I like the one where she has an ingrown unicorn horn."
She looked back to the Doctor. "Does that help?"
The Doctor smiled. "Yes, yes it does."
– – – –
The circumstances presented one option.
Go to the past and stake out Ponyville until Pinkie Pie miraculously appeared.
It wasn't terribly logical, but then again, neither were the circumstances.
The Doctor sat in the TARDIS, waiting. He was sure the event would be accompanied by some unusual energy readings, and he was going to figure out what was going on if it was last thing he did.
After about the fifth hour the Doctor got bored, so he went outside and stretched. He looked around. Some of the townspeople had noticed him, and briefly stopped, wondering why a man just came out of a small box, but most did not. Then he saw something in the distance that bothered him.
"Is that…?"
He started walking closer. First slowly, then, the clearer he could see it, faster and faster. When he finally reached the three ponies, they stared at him, worried.
Standing in front of him was what appeared to be a young Derpy, the real Derpy, no older than five, and her parents.
At first he wondered how that was possible, since he met Derpy on a space station. Then he remembered. She said the planet she grew up on looked like this. She must have been away long enough for her not to realize this was the planet she grew up on. Apparently, when she was a teenager, some bored space traveler whisked her away into space, and she hadn't been back since. The Doctor, curious, had pressed her for details, but she just said something incomprehensible about a pony with two heads and a heart of gold and dropped the subject.
He briefly wondered how the time bubble accounted for her being whisked away into space, since in the time bubble there was no space to be whisked away to.
"Can I help you?" what was presumably Derpy's father said.
The Doctor also remembered her talking about how, in her childhood, everyone thought she was mentally retarded because of her eyes. He knew, especially in contrast to her imposter, that she was perfectly smart. She just had a lazy eye.
Her imposter…
The Doctor thought back to that night. To that mutilated corpse that looked eerily like Derpy. At the time, he thought it might have been her from the future, but now he realized.
That must have been the real Derpy.
In this timeline, Derpy was inevitably heading towards her death.
He had to change things. He could save her. How didn't matter, as long as she ended up somewhere else.
"Oh, what a coincidence!" the Doctor said. "I was just about to make an appointment with you two."
"Who are you?"
"I'm the district superintendent," the Doctor said, showing them his psychic paper. "I wanted to speak to you about your daughter."
"Yes, we know she's underperforming," Derpy's mother said with some exasperation. "It's just… we don't have the money to look into treatment for her. You understand."
The Doctor subtly looked down to her perfectly manicured hooves. He remembered Derpy complaining about her parents being greedy bastards.
He got an idea.
"Treatment?" he said. "What are you talking about?"
"Can't you see?" Derpy's father said. "She's slow. Thick. Dence. Retarded."
"I'm talking," Derpy's mother snapped. She looked back to the Doctor. "As you can no doubt clearly see, our daughter's… disadvantaged."
"She most definitely is not!" the Doctor said. This was going to be risky, but as long as he could push her life in a different direction, he figured things couldn't end up too bad. "It's nothing but her eyesight."
"Her eyesight?"
"The teacher, bless her heart, I forgot her name, has been suspecting it for a while. She gave Derpy a pair of glasses and a standard intelligence test, and you know what she got?" The Doctor paused. "100%."
"100%!?" Derpy's parents looked at her in awe.
Derpy was dumbfounded at her apparently incredible performance.
It was all lies, of course, but he figured if he appealed to their egos enough they wouldn't bother to fact check. "If I say so myself," the Doctor said, "you have your hands on a latent genius."
"A latent genius…" Derpy's mother mouthed.
"Just give her a good pair of glasses, send her to a good private school in say, Trottingham, and mark my words, you'll have one of the forefront minds of our era on your hands."
"Wait, wait. Hold the phone," Derpy's mother said. "A private school? We definitely don't have that kind of money! And you're suspicious." She narrowed her eyes. "Why would you be telling us to take our genius out of your school?"
"For the same reason you should listen to me," the Doctor said. "Imagine if she does become one of this world's greatest minds. I'll be known as the superintendent willing to give up a special student for the benefit of ponykind. You'll be known as the parent that helpfully nurtured your daughter into a genius. It's an investment. If it fails, so what? You lose some money. But if it succeeds?" The Doctor smiled the most disgusting, moneygrubbing smile he could manage. "Our names will be etched into the history of Equestria. Not to mention the inevitable money."
Derpy's mother thought about it. "Well," she said, "I think this talk was very productive. We'll think about it. Thank you very much."
They walked away, both parents clearly deep in thought and Derpy wondering what the hell just happened.
The Doctor smiled. With any luck this would at least alter her life enough that she wouldn't end up traveling with him and dying. He walked back to the TARDIS.
On the way, he got a bit of a headache, but dismissed it.
– – – –
After a week, the Doctor figured he had missed whatever event brought Pinkie Pie into the world, and decided to go back to the present to investigate further.
What he saw when he opened the door was a bit of a shock. Instead of the usual, quaint Ponyville, which the Doctor had grown quite used to and was, despite his better judgment, beginning to like, he was in what appeared to be a large downtown district. It was nighttime, but ornate streetlamps lit up the roads, which bothered the Doctor because he thought technology hadn't reached that point in this world yet. In fact, the whole thing looked much more modern than what he was used to seeing on this world.
He approached a figure walking by.
"Excuse me," he said, "I'm lost. Where am I?"
"Ponyville University," they said, not paying him a moment's notice, and rushed off.
The Doctor thought. So, it was still Ponyville, but something changed it into a giant college campus. How on earth did that happen? Was it something he did? Logically speaking, it had to be, since he appeared to be the only time traveler in this world, but he couldn't imagine anything he did causing this.
Just thinking about it made his head hurt. He decided, for the moment, it would be best to do what he usually did in Ponyville: get lunch. Or dinner, in this case.
He entered the nearest pub, since it was one of the few businesses open this late. It was having a busy night, so the first thing the Doctor did was walk around, looking for an empty table. In the back of his mind, something bothered him.
After completely failing to find an empty table, and walking past the bar again, he realized what it was. One of the voices from the bar sounded familiar. It was a woman, clearly drunk, laying her life story on anyone who sat long enough to listen. Usually he wouldn't have cared less, but it sounded like someone he knew and he knew that was impossible. She had a strong British accent, and he hadn't met a single British person in this world. It couldn't be someone he knew from outside this world because they were all outside the time bubble. And yet…
He tracked the voice to its source, and when he saw it he nearly jumped out of his skin. That blonde hair. Those gray wings. Those bubbles. And were those… glasses?
"Derpy?"
She turned around, eyes wide. It was definitely Derpy, but something was different. The Doctor didn't get a good look because she promptly clocked him in the face.
"That's Dr. Do to you, wanker!"