"Doctor," asked Luna impatiently. "Are you going to let us back into your ship."
"Oh no no no," came a voice from inside the TARDIS, projected outwards by some unseen speakers. "I'm not letting you lot anywhere near my TARDIS. I mean winged unicorns? Clearly that's a work of fiction right there."
"And a two thousand year old alien in a time and space machine isn't fictional?" pointed out Candance. There was silence from the TARDIS, before the doors swung open again.
"Admittedly when put like that it does seem a bit far-fetched," said the Doctor slowly. "But I'm convinced of my existence."
"As are we," said Celestia.
"Oh well I'm sure you are," said the Doctor. "Just how robots might not know they're robots until you show them the wires running through their body. But as it stands, how can I trust something that clearly isn't real."
"We are asking ourselves the same question," said Luna drily.
"Why are we trapped here, Doctor?" asked Twilight, concerned that the sheer emptiness of the void and the lack of books therein would soon drive her mad.
"Because we're currently somewhere that doesn't exist and should never exist," explained the Doctor slowly, as if speaking to a child. "And if you're somewhere that's not meant to exist, soon you'll be something that doesn't exist. So if I don't get my TARDIS working, I'll be trapped here along with the rest of you."
"You're not going to take us with you?" asked Twilight in shock.
"Why ever would I do that? As I said, you're clearly fictional beings."
"But you can't just leave us here. However will we survive?"
"Oh no doubt you'll pop out of existence the moment I stop thinking about you," said the Doctor absent-mindedly.
"And if you pop out of existence when we stop thinking about you?" asked Luna. The Doctor paused, considering the idea.
"Well I wouldn't know either way, will I. Now if you'll excuse me, I have a TARDIS to fix."
"Will magic help," asked Celestia helpfully.
"As I've said before," said the Doctor, agitated, "magic does not exist."
"Neither do unicorns and alicorns, by your account," pointed out Luna. "And yet, here we are."
"It wouldn't hurt to try, would it Doctor?" asked Candance hopefully.
The Doctor said nothing, mulling the situation over in his head. Finally he came to a decision.
"Oh all right then," he said sourly, opening up the TARDIS doors and ushering the equestrians inside. "But if this doesn't work than I'm leaving you here."
"And if we can teleport home we'll do the same," replied Luna.
"Deal," said the Doctor absent-mindedly, as he got to work.
"Are you sure all this is necessary," asked Candance, as her eyes went cross-eyed looking at the wires being attached to her horn.
"Quite sure," said the Doctor. "You need to feed all your power to the TARDIS' main power conduits. That should give us enough of a kick-start to get us moving and, hopefully, get you home."
"Get us home?" asked Twilight excitedly.
"Well if a colossal burst of energy got you here, it's entirely reasonable to think that another burst of energy will send you right back, with my ship along with it. If all four of you focus on teleporting back to your home, then I'll at least be back in real space-time."
"And you're sure this will work?" asked Luna cautiously.
"Not in the slightest," said the Doctor. "But it's better than nothing. So on the count of three get ready to charge up. One… Two… Three!" The Doctor slammed down a lever as the four horses powered up, the light quickly engulfing the TARDIS. The Doctor shielded his eyes, wishing he'd thought to grab his sonic sunglasses, as everything went a blinding white…
When the Doctor could see again, his four-legged companions were exactly where he left them. Which clearly up the question of whether they were fictional or not. He quickly checked his instruments, relieved to find that he was occupying a real part of space-time. He didn't recognize the co-ordinates, but it didn't matter. At least he was in his own universe.
"Did it work, Doctor?" asked Twilight hopefully.
"We're somewhere real, if that's what you're saying," said the Doctor. "Fortunately the TARDIS is going to take time to recharge its batteries. A good twenty-four hours I think."
"Where are we?" asked Celestia.
"I don't know," admitted the Doctor. "But there's only one way to find out." Confidently he strolled forward and flung the doors open… only to fail to recognize the town that lay out before him. His companions, however, let out a gasp of joy.
"Doctor," said Candance. "We're home!"