“Okay, I’m beat. I have no idea what this thing is for.”

Scootaloo and Flight had been standing at the foot of the door for a couple minutes, trying with all their might to try and get it open. There was a very obvious lip in the centre of the door, separating the two sides, but it was sealed shut with no way for the fillies to pry it open.

“It’d be a lot easier if we had magic,” Flight grumbled. “Where’s Kevin when you need him?”

“I’m sure Kaylee is doing just fine right now,” Scootaloo shot back. She tilted her head up, trying to get a better look at the hole in the centre, at about her eye level. Although the circle’s width was smaller than the size of her hoof, meaning she couldn’t just reach through, Scootaloo was still able to see the ridges that lined the interior of the door. Beyond lay simply darkness.

“Lemme get a look!” Flight suddenly shoved Scootaloo out of the way, sticking her own face up into the hole. Grunting, Scootaloo stepped aside and trotted a few steps away, closer to the room’s corner.

“Yo, Grey,” Scootaloo said in a low voice. “You got any ideas about this door? Those pipes up there won’t hold forever.”

For a moment, she waited. No response came.

“Scootaloo!” Flight called. “What are you doing? C’mon, we need to try and get through here!”

Scootaloo sighed, and turned back to face the yellow pegasus. “Yeah, and I was trying to look through before you butted in.”

Flight rolled her eyes. “Excuse me for wanting to know what was going on. You could have at least left me space to squeeze in.”

Scootaloo tapped a hoof to her forehead. “Whatever. Arguing about it isn’t going to help anything.” She turned back to the door, and examined the ridges of the hole once more. And as she looked, she couldn’t help but notice that the ridges looked… familiar.

“Huh… that’s strange.” She leaned in closer.

“What is it?” Flight asked.

Scootaloo leaned back, and pointed at the hole. “See here? The shape of the ridges? I’m pretty sure that the end of the key is shaped like a gear.”

“Hmm.” Flight looked up. “How does that help us, though?”

Scootaloo looked confused. “What do you mean?”

“Like, how are we going to get inside?” Flight asked, gesturing exasperatedly with a hoof. “I dunno if you’ve noticed, but there’s nothing else in this room besides us.”

Scootaloo turned, and looked at the otherwise empty room. “Erm… well…”

“Well, whatever.” Flight harrumphed and then curled her hooves beneath herself, sitting down. “Guess we’ll just sit and wait for the guards to get here. Hopefully they can put me out of my misery.”

Scootaloo groaned. “Seriously? You’re not going to help?”

Flight didn’t even look at her as she responded. “Help with what? If you haven’t noticed, we have a dead end unless we can get through this door—and I have no idea how we would do that. There’s nothing else to do.”

Scootaloo bit her lip. Then, she took several steps into the body of the room.

“Grey,” she murmured, once she was sure she was out of earshot. “Please. I need your help. You’ve gotta be up there.”

No response.

Scootaloo sighed. “Don’t make me reach my hoof up there and—huh?”

Just as she was speaking, the filly noticed the back wall of the room—which hadn’t really caught her attention before, since they had been facing the other way. And at first, it didn’t seem like much a sight to behold; that half of the room was empty and, besides the duct above they had sprung from, most of the wall was taken up by designs, lines that formed hyperbolas echoing out from the centre.

But as Scootaloo moved closer and tilted her head, squinting her eyes… the round shape in between all of the curves looked mighty familiar.

“A gear…” she breathed.

“That’s what you said before,” Flight called from behind her. “But there still aren’t any gears around.”

Paying Flight no mind, Scootaloo continued on until she was only a few tail-lengths from the metal surface. At this point, she was able to see that it was most definitely a gear shape in the wall—and, what’s more, it seemed to protrude from the wall by about a centimetre.

Experimentally, Scootaloo gave the front a light tap. It had no give; she was in no danger of accidentally getting it stuck further in the wall. Breathing a sigh of relief, she lifted her forelegs and, carefully, put a hooftip on either side. Her balance was stable enough for now, but it wouldn’t last for long. So, without further ado, she started pulling.

It didn’t come easily, and Scootaloo found it difficult to keep her hooftips on the almost-sheer metal sides, especially with so little to hold onto. Still, she was pretty sure she was making some progress; more and more of the side became visible, and it started to feel looser in the socket.

“What’re you doing?” Flight suddenly called out.

Scootaloo, surprised, nearly jumped, and she lost her balance. She let out a yelp as she fell forward, pushing the gear back into its slot and then she slid down the wall on her face. “Ungh…”

As she lay on the ground, Scootaloo could hear Flight’s hoofsteps behind her. “Um… are you okay?”

“Y-Yeah,” Scootaloo managed as she started to pull herself up. “Just… just dandy.” Once she was settled on her hooves, she took a look at the gear. The gear which was now just another part of the wall, no longer jutting outwards.

“Crap!” she exclaimed, fuming. Her brow furrowed. “Ugh… what are we gonna do now?!”

Flight blinked. “I don’t understand. What were you doing?”

Scootaloo whipped her head back, her face livid. “I found the gear! Right here!” She pointed at the gear shape on the wall, tapping it loudly. “And I almost had it out, too, until you had to up and surprise me into pushing it back in! Now we’ll never get it out…”

“Oh… um… surely it can’t be that bad, can it?” Flight leaned in, getting a closer look at the gear. “How did you get it out in the first place?”

Scootaloo groaned. “It was already sticking out a bit, and that’s how I was able to get my hooves on it. But now…”

“I… I’m sorry,” Flight said weakly. “I didn’t know.”

“I know,” Scootaloo said with a sigh. “Ugh, sorry. There’s no reason to blame you. I just… I’m nervous. I don’t know what we’re going to do now.”

The two fillies stood there in silence for a moment, looking from one another to where the gear shape was set in the wall.

“We could—” Flight started, but she was interrupted by Scootaloo’s hoof on her lips. She blinked, confused, and then saw Scootaloo jerk her head to the side. Following the motion of Scootaloo’s head, Flight looked back at the door on the other side of the room. It looked the same as before… except the hole in the centre was glowing, glowing with that same bronze colour. The light then slid up into the crack between the two halves of the door, causing the room to shine even brighter.

“We did it!” Flight exclaimed. “It must have been a button!”

“I’m… I’m not sure about that,” Scootaloo said, her tone nervous.

Flight turned back to look at her. “What do you mean?”

“Look,” Scootaloo breathed. The two sides of the door began to split apart, and another layer of bronze light bathed the room, this time much like the thickness that had filled the air just as they came in from the duct. They could hardly see a thing before them through the mist.

“I… I hear hoofsteps,” Flight murmured, and as she said that, Scootaloo could too. Loud, booming hoofsteps, belonging to somepony large.

“It wasn’t us who opened the door,” Scootaloo said. “It was… whoever that is.”

Flight gulped. “What… what should we do?”

“What can we do?” Scootaloo asked, turning to her companion. “What can we do… but wait?”

Flight said nothing. The hoofsteps grew closer.