The Riddle

Darkness.

Twilight immediately realized that things had gone wrong. It shouldn’t be dark. She had teleported with a light spell already cast. And the weight on her back shouldn’t be gone... but it was.

She lit her horn again, only to be rewarded with a sinking feeling of crippling fear. Gray light illuminated something far larger than the tower. Only a dark wall beside them was visible.

“Your saddlebags are gone, too,” Rainbow Dash said. “Twilight, what’s going on?”

“I don’t know,” Twilight whispered. “Rainbow, the light shouldn’t be gray.”

“What?”

“Unicorn magic is always bound to a color. Mine is purple. If I cast light, it’s purple. It’s never gray. It shouldn’t be gray.”

“It’s messing with-”

“That shouldn’t be possible!” Twilight hissed, for a moment close to panic. “You can’t mess with magic! That’s not how it works! That’s how ponies who have no idea think it works!”

“Twilight! Calm down!”

Twilight said nothing.

It wasn’t that landing in a larger place was unexpected. Dilation magic was feasible. Earlier, during their preparations, Twilight had argued that, based on the level of ability the tower had demonstrated thus far, they should account for the possibility of its insides being significantly larger than the space it occupied. But it didn’t matter, because almost all of their preparation was lost. The food they had packed was now just as useful as their pre-charged crystals, their candles, clothes, lighters, the phile of preserved dragon fire, their compass...

“Are you sure you didn’t do anything different-”

“Yes.”

“Okay. Relax, Twilight.”

Twilight nodded. “It’s also not as bright as it should be... let me see...”

She increased the flow of magic and the light brightened, but not as much as it should. Apparently, a bigger toll of magic was now required to achieve the same effect, which, once again, should not be possible.

The increased light had neither illuminated another wall, nor the ceiling. Twilight brought it back down, closing her eyes.

“I can’t teleport,” she said after a moment. “it’s blocked.”

“Awesome,” Rainbow said cynically. “So we’re trapped.”

“Yeah.” She sighed. “I guess we have to walk.”

“Ahem.”

“What?”

For a moment, they looked at each other. Then, Twilight noticed the pegasus demonstrably flapping her wings.

“Oh! Right!”

Rainbow grinned.

“But we might be in here for while. Won’t it be too exhausting for you?”

“Nah. I could fly you around for hours, if I have to.” She held her wings outward and lowered her hind legs, clearly signaling Twilight to climb onto her back. After a moment of hesitation, she complied.

The pegasus’ body was warm to the touch. She had expected that; out of the three races, pegasi had the highest body temperature, and unicorns the lowest. What she hadn’t expected was how intimate it felt, her hooves wrapped around Rainbow’s neck and their bodies pressing together. This must have been why pegasi carrying other ponies was such a rare sight, even though everypony liked to fly.

“Ready?”

“Yeah.”

Twilight held her breath, then they were suddenly in the air. It had gone so fast that she was still processing it, taking a few moments to realize that Rainbow had said something. Something.

“Come again?”

“Where should we go? Up?”

“Oh. Um, yeah. Let’s see how high this thing is.”

“Alright.”

They ascended. Slowly, as their only guidance was Twilight's own, dim light. She hadn’t expected for it to take more than a few moments, but as the seconds crept by, they just continued ascending higher and higher, the ground long out of sight. Save for the one gray wall, the darkness was absolute.

“This is creepy.”

Twilight said nothing. She noticed her heart beating faster than normally, and wondered whether Rainbow would be able to feel it.

After a while, she decided to once again to increase the flow of energy feeding the light, a choice she was immediately grateful for.

“If I’m not even walking myself...” she murmured. “This way we’re less likely to crash into the ceiling.”

Rainbow’s response was to fly faster. Twilight bit her lip. That was not what she had intended, but she didn’t complain.

They continued. A minute passed...

... and more seconds kept creeping by. How long had it been, now? Ninety seconds? Too long.

“Stop,” she heard herself say. “This isn’t good.”

She could feel a moment of weightlessness as Rainbow halted in her ascent, then they were back to their slight hovering, up... down... up... down...

“If it’s a simple dilatation spell, and the tower is empty, then going up will take much longer than going forward.”

“Should I get us back down?”

“Uhm. I’d try to fly along the wall. If that’s easier when we’re near the ground, you can go back down, but if not you can stay at this height. I just don’t want you to get exhausted. Flying upwards can’t be easy.”

“It’s fine,” Rainbow said, and there was a sudden pull to Twilight’s hooves as she began to fly forward, parallel to the wall. “I’m not exhausted that quickly.”

“But f-flying...” She interrupted herself at the sound of her own words. Had she been stuttering? That was so unlike her. “... upwards must he harder than going straight.”

“Sure, but it was just a few minutes. I’m fine, don’t worry.”

Twilight closed her eyes, then opened them at the sudden rush of claustrophobia. What was wrong with her? Was it because of Rainbow?

... no. She’d like to believe that. That would be harmless. Cute, even. But it wasn’t true. She was afraid, simple as that. It seemed as if the tower was hollow, with the same shape as seen from outside, but far, far larger. There was then no guarantee whatsoever for a way out to even exist.

Suddenly, Rainbow Dash slowed down, causing Twilight, who hadn’t been ready for a thrust in this direction, to be pushed forward, instinctively summoning her magic to stop-

“Aaahrgh!”

“Sorry!” Twilight shrieked, her heart now racing. “Sorry sorry sorry!”

“Ow... what was that?”

“You, you slowed down so abruptly and I was losing my grip I so, I, um, I helped out a little with magic, and-”

“It felt like someone hit me at the back of the head with a rock!”

“I had to push against something!”

“Ow,” Rainbow repeated. “Ow. Okay. Don’t do that again.”

“I promise. Sorry.” Then, “thanks for not... uhm, dropping me or something. You reacted great.”

“Used to stuff like this,” Rainbow murmured. “Okay, so the tower’s not all empty.”

Twilight nodded, only to realize the uselessness of that gesture.

“Yeah.”

The reason why Rainbow had slowed down so abruptly was the wall that had appeared in front of them – although, in the end, they had come to a halt several yards early. Perhaps she wasn’t the only one who was nervous.

As Rainbow flew closer, Twilight could see that the former wall was simply bending into the new one; a rounded corner. At least now, there were walls on two sides. Little as it was, it seemed to diminish the earlier sense of being lost a bit.

“What now?”

“Hold on,” Twilight murmured, reaching out with her senses. To her surprise, she found not what she had been looking for, but instead –

“Fly up again.”

“Huh?”

“There’s a ceiling. Close.”

As Rainbow ascended further, Twilight realized she’d been wrong. What she had thought to be a ceiling was merely the wall bending outward and then inward again, forming a sort of ring, a bulge, or a platform. Judging from what little part they could see, it appeared to be protruding equally far out of the wall at all points. Where the wall itself bent, so did the bulge.

Without hesitation, and before Twilight could warn her (if she had wanted to), Rainbow landed on its top. It was perhaps ten yards wide, though less than half of it was even enough to stand.

“Is this one of the spirals?” Rainbow asked. “You told me the tower had spirals to it. If they bulge inward...”

“I don’t think so. It’s too even. Horizontally, I mean. If it was one of the spirals, it should be like a large slide.”

“Don’t you want to climb off?”

“Um,” Twilight made. “Um.”

“You can stand no problem here. Just don’t go too far forward.”

“Can you turn around first? I want you to be able to catch me if...”

Rainbow turned on the spot. Twilight climbed off, then turned around to face the wall again. This way, the platform sloped upward, like a ramp, until it merged back into the wall.

“Be still prepared to catch me,” she murmured. “Just in case this thing disappears or something.”

“Okay.”

“Also, thanks,” she said, turning to face her friend. “I’m glad I didn’t go alone.”

Rainbow nodded. She didn’t say anything about being trapped, that Twilight had potentially endangered both of their lives, or about the incident from before. Twilight felt a sudden, unexpected wave of sympathy.

“What do we do now?”

“Give me a moment.” Once again, Twilight reached out with her senses, and once again, she was surprised.

“There’s a real ceiling. Not that far up.”

“You want me to fly us there?”

“Can’t hurt.”

Rainbow nodded. “Jump on.”

It was less awkward this time. Twilight had already learned how it would feel, and a bit about how to stay firm without tightening her grasp too much. She could feel that Rainbow was flying more slowly now, but it still didn’t even take half a minute to reach the top.

Neither of them probably had expected anything else at this point: once again, there were no edges, the wall simply bent to slope over their heads, forming what must be a sort of dome. It was hard to judge how exactly it was shaped, given that all they saw was a tiny, poorly lit sliver.

“Where now?”

Twilight suddenly realized how naturally Rainbow turned to her for directions.

“I... I think follow this for a bit, then if... everything is normal, you can fly back down.”

“Alright.”

With steady wingbeats, Rainbow flew them forward, inches below the dome and still parallel to the wall. Twilight wondered whether they really were at the tower’s top. She doubted it. The actual tower was too thin near its top. This was so wide that she couldn’t even tell whether it was still bent, and as she asked Rainbow, neither could she.

The flight downward frightened her more than anything before. It seemed like a fall. Like they both were falling into an infinite abyss, with nothing but a gray wall beside them.

Then they reached the ground.

“What now?”

“Let me think,” Twilight said, trying to visualize the route they’d taken. “... okay. Fly further. But stay low.”

Once more, Rainbow did as she was told. Twilight kept her gaze at at it, searching for kind of irregularity, but finding none.

And they flew.

And flew.

The passing of time didn’t serve to ease her worries. In the best case, they were now passing along the tower’s diameter, and even then, every second meant she had to adjust her estimate of the interior’s size further upward. They most certainly hadn’t reached the ceiling before. If proportions were preserved, the tower was far, far higher than the meek distance they had bridged earlier. A hundred times as high, and more by the second.

“How does dilatation work, Twilight?” Rainbow eventually asked, without slowing down.

“Magic?”

“Yeah.”

“You take the space you need from somewhere else. You can’t create it. You also can’t move it, not really. But you can tell the world that it’s now where you want it to be. Imagine you have a map of a mountain, and you want the route upwards to be shorter. You can’t change the mountain, but you can redraw your map, and you can try to convince the world to accept your new map in place of the old one. Dilatation works just like that. You take a large space from somewhere, and you convince the world that this space is now inside the tower. But in truth, it’s not. In truth, subjects entering the borrowed space are in essence teleported to wherever the space really lies, but for us it’s impossible to tell the difference. The borrowed space bends around the real space perfectly.”

“And where do you take it from?”

“Any place that will stay abandoned. Um, you see, you changed the entry points of the space you tried to move. If I take the inside of the library and convince the world it’s now in Sugarcube Corner, then the new way of getting into the space of the library is now through Sugarcube Corner – not through entering the library anymore. But, if somepony tries to do it the old way and enters the library, things go wrong. The world realizes it’s been lied to, so it tears up your new map and goes back to the old one. You have to take it from a place that no-one will enter. Like a sealed room. If you don’t have that and you’re strong enough, you can look for holes in the earth. Empty caves. The earth is full of that. The farther you can go, the more likely it’ll stay empty. Animals only go so deep.”

She hesitated.

“But this is too large for a cave. And you can’t add places together.”

“Just take a piece of the sky?”

“Can’t. There are birds which fly miles above ground, and you need some proximity to matter. Don’t ask why. That’s why caves work. It could... be a large, empty stretch of land somewhere. Far away. I don’t know. Or... on the moon, I guess.”

“Isn’t that too far?”

“I don’t know. Too far for me.”

They kept flying. Twilight thought Rainbow’s wing beats were getting more forceful, less smooth. But perhaps she was imagining things.

“So we’re not even really in the tower.”

“No. Not really.”

“We’re on the moon.”

“Maybe.” Twilight gulped. “Probably.”