There was a rather convenient but fairly long and steep ramp going up and around the entire plateau, apparently it had been carved into its rather rocky stone sides. Though neither expected to end up at the Academy, it was soon that they realized that they weren't at the Academy, exactly. Near the top of the plateau, only about fifty feet down from it actually, there was a strong magical signature coming from a section of rock. Rarity's horn stopped glowing and the chariot came to a stop.
"Where are we?" Charlie tapped the rock with a hoof, it gave off a similar 'zap' feeling to being on the receiving end of static electricity.
"The spell seems to think we've arrived, as such we must be at the entrance. It might be a stretch, but let me try something." With that, Rarity powered up a spell similar in magical signature to the first. An outline of an arched doorway formed and the door creaked open as if the huge mass of rock was on hinges.
"That was great. Thanks, Rarity." And with that, he cautiously trotted in. There was a long, dark tunnel with a light at the end. He walked in darkness and in almost pure silence, save for his and Rarity's hoofsteps, toward the light. Slowly the floor beneath their hooves became not dirt but tile, first slightly beat-up then progressively more polished. Their hoofsteps got a little louder as they trotted over the tiles.
They heard a voice, it was almost definitely female and sounded fairly young. She seemed to be mumbling to herself, they got close enough so they could see a room being lit by several fluorescent light bulbs and the mumbling stopped. They heard what sounded vaguely like the unsheathing of a sword of some kind before a pony jumped out in front of them, blocking their path. The pony's coat was orange and her hair was fuchsia, her eyes a dark magenta. Though the pony would normally have looked completely harmless, she was pointing a samurai-sword-like weapon at them. The fact that she was shooting daggers out of her eyes made it a slight bit more intimidating.
"Who are you and how did you find me?!" she demanded.
"Careful with that sword, darling, you might hurt somepony." Rarity gently tugged the sword out of the pony's magical grasp and tossed it aside, it made a clattering noise against the tile. "Now. I suppose you are Crystal Charmer?"
"How do you know my name? Who are you?" her voice sounded more worried than threatening now, it actually sounded like she was angry and sad at the same time.
"My name is Rarity, this is Charlie, and we don't mean to hurt you." Rarity walked over and patted the filly's head. In response Crystal swatted at her hoof as if it was a large bug trying to sting her.
"I don't want you to put me down just cause I'm young! Foals have rights too!" Crystal half-screamed.
"True, but last I checked there was no law saying I couldn't pat somepony on the head to be friendly."
"You're not being friendly, you're being condescending!"
"My my, what big words for a filly!"
"See?! You're telling me I'm not allowed to be sesquipedalian purely because of my lack of experience and my youth!"
It was then that Charlie spoke up. "I know what that's like – people talking down to you just because you're young. But lashing out at them isn't going to help, it's just going to make them mad, or worse, they're going to think that's just you being a kid and you being childish."
"Congress ponies get up and shout at each other all day long and nopony calls them childish," Crystal pointed out, though she sounded much more like she was just stating a fact than like she was being immature and hostile.
"You're right, they don't," Charlie laughed, "But between you and me, I think somebody should."
"Agreed," Crystal nodded, "If you can get your 'friend' over there to stop treating me like that, I'll show you guys around."
"I'm not sure what I was doing to upset you, darling, but you have my word that I shan't pat you on the head or in any way lead you to believe that I care about you."
"Thanks. Alrighty, well, you might've guessed from my cutie mark that I'm a mathematician. You'd be right. I'm also a writer and an artist, though. I really love doing math, but I don't really classify algebra as 'math'. I classify algebra as 'annoying'."
"It can be tedious at a few points, but I'd hardly call it 'annoying'."
"Yeah, I did guess that you were a mathematician."
"Most ponies can guess that much."
"If you don't mind me asking, how old are you?"
"Oh. I'm 12. And I don't mind you asking, no. By the way…" Crystal levitated over a donut from one of the boxes on the island in the center of the room and offered it, "Want one?"
"No thanks."
"Mm." She took a bite as she shrugged. Her next sentence was muffled a bit by the donut in her mouth, "Your loss."
"I do so enjoy the style in which you've decorated your room, darling." Rarity looked around the room. There was a whiteboard entirely covering one wall with a bucket full of colorful dry erase markers on one edge. There was a mini-fridge in the corner stocked full of diet sodas; a stack of ordinary, Earth-style printer paper on top of it. There were several sheets of blank paper tacked up to the far wall. There was a twin-size bed with pink covers. The island's marble countertop was almost entirely covered with snacks – an open box of frosted corn flakes; a stack of boxes of chocolate frosted mini donuts, the recently opened box that she'd just taken the donut from next to the stack; a previously opened, partially finished half-gallon of chocolate milk; an empty bowl, a used spoon in it; and a box full of seemingly fresh French fries as if someone had come with new ones only a few hours ago. That worried Charlie just a little.
"Thanks," Crystal replied.
"You're welcome, darling. If I may ask, though… what are these for?" Rarity gestured to several notes scribbled on the whiteboard within boxes of various colors.
"Oh. Stuff for my writing. See? I have 'Shana becomes a human in the next chapter and tries to cope though her coltfriend is still in Equestria'… Shana is one of my characters who gave herself a human name cause she'd rather be a human. But, see, she's torn between her dream of becoming human and her coltfriend, who refuses to leave his old man in Equestria."
"I think that'd be a great story."
"I haven't worked on it for a while… cause what's the point of writing fiction when your life is an adventure, right? That and I kinda have a bunch of work to do…" Crystal gestured to a note that said in all capitals, "GET THE BLUEPRINTS DONE TOMORROW, OR ELSE!"
"Blueprints for what?"
Crystal sighed. "You shouldn't know this… but if you swear not to tell anypony…"
Charlie did the motions for a Pinkie Promise, non-verbally swearing that he wouldn't speak a word of whatever Crystal told him next.
"Alright." She pulled out the tacks supporting one of the blank sheets of paper and flipped the paper over, revealing a rough blueprint of a modified rifle. The trigger was made much larger to allow for somepony to pull it with a hoof since ponies have no fingers. Otherwise the mechanisms were roughly the same, though several specific places were made larger to allow for usage with hooves.
"You're designing guns?!"
"Magic fields can be broken with sufficient physical force. Guns are specifically designed to use significant amounts of physical force. Though it took the Queen's entire changeling army weeks to beat through the shield, it would take a pony with a gun a maximum of an hour. We could rule Equestria while barely requiring any magic!"
"Whose idea was this?"
"…Can't tell you that."
"When did they hire you? And why?"
"Can't tell you that either. I can tell you that, in a week, Equestria will be ours."
"I've read enough stories to know that after the antagonist says something like that, they try to kill the protagonists."
"I'm not an antagonist, first of all. I'm the protagonist. I'm the spy for the inside that didn't even used to know she was a spy. You ponies aren't the protagonists. You're not on my side. I'm on my own side. That's why I'm not gonna kill you. At least right now. You were and still are free to go. Unless, of course…"
"She's gonna offer for us to join her."
"…You want a donut."