The machine was alive around her. It pulsated and thrummed with its own strange, syncopated rhythm. Dim lights glowed from the walls, and though the path before her opened up into a darkened, cavernous shaft, she could not see its end.
Derpy flew forward, surrounded by aeons of corrosion and the grinding of a million gears. A giant crankshaft spun through the center of the corridor, and several times some bow or protrusion of it swung within inches of her body. Once, a giant cog crashed through the works of the machine, and nearly struck her as it careened through the darkness. Another time, a giant spring a hundred feet high gave her no choice but to risk flying between its coils as they compressed and decompressed. Everywhere, fire roared suddenly from grates at intervals that had no predictable rhythm. It was a place of perfect, ultimate madness; a clockwork marvel where no part seemed bent to any intelligible purpose.
She was pursued every inch of the way by plaid murderbots, all swarming, diving, and rolling through the lethal, metallic labyrinth. Paths branched left, right, up, and down, and somehow the bizarre, huge, spinning shaft managed to split to follow all of them. No matter how many of these paths she took, Derpy was never in the least certain that she was headed anywhere closer to her intended destination, which itself she could not imagine.
She followed these paths until at last one gave way to a massive cavern. Here, there were no more killbots, the last of them having plowed into a wall behind her some minutes ago, but she was reminded immediately of the Doctor's promise that the machine was bigger on the inside. She could see no wall of this place, but there was light everywhere; the light of huge buckets which carried some strange fluid upward on long chains from some unseen reservoir far below, only to turn over at the top of their travel, and dump it back once more. It was the liquid itself that glowed, she realized, painting everything with a pale, blue light that still was not enough to show her how far this void might stretch.
There was nothing for her to do but choose a direction, so she did. She flew forward, wondering how far this strange, darkened place might extend into the bowels of the engine. At length, her wings grew weary, but there was nowhere for her to set her hooves. She flew downward, hoping to find some platform where she might take her rest, but none presented itself. There were only the buckets and their chains. As far as she knew, the roof of this cavern might even extend well above the place where she had seen the peaks of the chain drive mechanisms that carried the buckets. Fearfully, she found one of the buckets that was on its way down, and gently lowered herself into it so as to rest her wings for awhile. Out of curiosity, she peered over its edge, and waited to see how far it might carry her before reaching the source of the weird, glowing water. She waited for as long as she could stand without seeing any indication that she was even beginning to approach the bottom, and hopped from the bucket, flapping her wings once more.
It struck her then that she had no idea of what direction she had originally been heading. There was a moment's panic and a further moment's despair, but she knew she could not allow her fear to take hold. She chose once more a direction, and flew onward, unsure of what it was she searched for.
Eventually, after her wings had grown weary several times more, forcing her to rest herself in the buckets, being carried ever lower each time, she found a high wall of some gleaming white metal that reflected the pale light of the rising buckets and the shower of droplets they released from above. The wall was fitted together of many plates, angular and varied in their size. She scoured its surface for what might have been hours for all she knew, finally coming to a large opening very obviously meant to serve as a door. A long bridge of what appeared to be black granite extended away from it into the darkness, and it had an arched entryway, trimmed with an elaborate, curvilinear border.
She flew to the black granite bridge, and set herself down upon it. She could not guess how far it went on into the blackness, and the door seemed, insofar as she could remember, to be in the direction nearest to the machine's center. In this insane place, there was no reason for her to assume she would even find the machine's power source at its center, but there was no greater reason to assume she would not, either.
She walked towards the door, which led into a tunnel lined with more of the silvery, reflective metal. There was no distinctive feature of this tunnel other than its mirror-like inner surface, and it caused Derpy to be reflected in multiples of herself in any direction she turned other than straight down the tunnel, itself. She walked forward for some time, growing ever more certain that she had taken the wrong path, until finally the tunnel opened to a large chamber.
The chamber was made of massive panels of marble. The only light came from a strange, glowing coil that protruded downward on a long stem of blue-black steel. How far this stem rose upward was impossible to discern, for the chamber seemed to climb upward forever, its walls terminating in no visible ceiling. There was also a massive obsidian door at the other side of it, covered in more of the weird geometric patterns that she had seen on the machine's exterior. Like everything about the engine, they seemed to point to nothing and to have little rhyme or reason to their layout.
It was not the chamber itself or even the door that most unsettled her, however. The inside of the machine was like nothing she had expected, but it had left her in a state that would have made it difficult for almost anything to surprise her. The one thing that could, however, was to find something alive and biological in a place that thus far had been nothing but dead and mechanical.
At least she thought for a moment that they were alive.
All around the room, in over a dozen tubes filled with some cloudy, grayish fluid, were suspended the bodies of many different kinds of animals, and each of them was missing some part of its body or other. In only a moment, it struck her that each of these missing pieces corresponded to a part of discord's own body.
There was a lion missing a foreleg, a young dragon missing its tail, a goat missing one of its horns, and a deer missing one of its antlers. There was a snake whose mouth hung open to reveal it had no tongue, and an eagle lacking one of its legs. Indeed for every part of discord, there was an animal, but strangely, none of their bodies showed wounds where these parts had been removed. It was as if the part that was missing had simply never grown there.
Derpy came slowly to the realization that these creatures were not alive. They hung still and lifeless in their tubes, their eyes open but glassy and devoid of life. They were not a threat, nor in any state of pain. This somewhat assuaged Derpy's fear and unease, but then the dragon spoke.
"Who are you?" it asked, producing a yelp of surprise from Derpy.
It did not move in its tank or turn its head to face her. It continued floating just as it had been, its mouth moving though its eyes never blinked or so much as turned towards where Derpy stood. It's voice was like Discord's, though much deeper in proportion to its size, and it caused the entire, marble room to vibrate slightly. The sound seemed to come from everywhere at once, and Derpy wondered if it was not the room itself that made the sound, rather than the vocal chords of the pickled creature.
"Uh," said Derpy, having settled herself from where the dragon had startled her. "I'm Derpy... Or Ditzy. Whichever."
"What are you doing here?" asked the goat with the missing horn, its wavering, sheepish voice once again similar to Discord's in its own way.
"I'm looking for Discord's impossible dream," she said. "It's supposed to be what powers this machine, isn't it?"
"Correct," screeched the eagle.
"And incorrect," grumbled the lion.
Just like the dragon, not one of these creatures showed any sign of life beyond the moving of their mouths as they spoke. It made Derpy want to turn around and run away, but she was too close to turn back now.
"Incorrect?" asked Derpy, turning her head to look at all of the animals floating in their tubes.
"Precisely," bellowed a bull that was missing one of its legs.
"And imprecisely," squeaked a large bat that was a short a wing.
"You're not making any sense," said Derpy. "It can't be one and not the other! Am I right, or am I wrong?"
"You are right in coming here to search for Discord's impossible dream," said the dragon, "but you found it the moment you entered. The machine is Discord's dream."
"No, it's not," said Derpy. "He told me so himself; this machine isn't his dream, anymore."
"Then the dream has become larger than the dreamer," said the lion. "So it goes. Now, Discord himself is the dream, the machine the reality."
"That's insane," said Derpy.
"Of course," said the deer. "All worthwhile dreams seem like madness to everyone -- especially the one who dreams them. They are so absurd, in fact, that rarely does the dreamer believe it when at last they come true."
"Discord doesn't want this dream to come true!" shouted Derpy. "He sent me in here to stop it!"
"But it cannot be stopped," said the bat. "It has already come true. It has made itself real against all odds."
"The pattern will be perpetuated," said the dragon. "That is the nature of the machine; the nature of Discord's dream fulfilled."
"No one and nothing can stop the engine," said all the creatures in unison.
"Not even Discord," said the deer.
"And certainly not you," said the goat.
At this, Derpy's heart sank. Nothing the creatures were saying was helping. It all made no sense, and seemed to lead nowhere. It was like the whole, preposterous machine, itself: a collection of mindless, circular fragments of ideas and explanations that never quite linked back into a cohesive whole.
Could it be true? Could the machine's very nature really make it completely impossible for it to be stopped? Had she come all this way in vain?
"Of course I have," she mumbled to herself.
"What?" asked the lion.
"I'm just little Derpy Hooves," said the Pegasus. "I can't stop a probability whatsit."
"Correct," said the goat.
"But that's never stopped me before," she said, "so I'm gonna keep trying."
"Fool," said the bat.
"Yep," said Derpy. "Sure am; is that door locked?"
She gestured at the huge, obsidian door on the other side of the room, but there came no response to her question; only a long silence.
"Uh... yeah," the dragon finally said.
"Impenetrable to even the mightiest being that reality could ever allow to exist!" cried the eagle.
"But I'm not that," said Derpy.
"Surely then," cried the bull, "if that door can halt such a being..."
"...it can stop such an insignificant thing as yourself!" said the goat, finishing the bull's sentence.
"Absolutely!" shouted the bat.
"It will yield to no one!" exclaimed the lion.
"Mmmhmm," grunted the tongueless snake, actually nodding, though the action was stiff, and its eyes still did not move.
Derpy looked around at the circle of floating, not-quite-whole animals.
"Well, would it be a problem if I just... tried it, then?"
"YOU WILL FAIL!" roared all of the beasts.
"But you can't actually, physically prevent me from just giving it a little push?" asked Derpy.
There came the sound of grumbling and huffs from many of the tanks, but no creature's voice responded.
"Well," said Derpy, "I'm gonna try. Can't hurt."
She walked past the dragon's tank, and gave the door a push. It swung open with a creak, offering almost no resistance. She turned and looked back into the room.
"Guys," she said, "it opened. It, like, doesn't even have a lock, I think."
None of the animals responded.
"I'm gonna go on ahead, now," said Derpy. "You guys... uh... you have a nice..."
She stopped for a moment, and scratched her nose.
"You know what?" she said. "You're jerks."
She turned and walked through the open door.