[FROM THE MIND OF STRONGHOLD]

"Well, what are you waiting for? Walk through!" Celestia's motivation scared me enough to heave my sorry flank through the portal. One split-second of disorientation later, and I found myself to be on the other end of the fence. Eeyup, that may never get old. I stepped to my side to allow Celestia to come through the portal. "Okay, since it looks like you don't need help with aiming the device, let me show you this."

She took aim with her portal gun and shot her two portals at the floor beneath my orange one, and the other on a nearby wall, but about twenty feet higher. I was more alarmed by the fact that her portals were red and purple than that she was trying to catapult me to a ledge. "Okay, now what?" I asked.

"Well, since it looks like I'm going to be the one to teach the things that GLaDOS didn't, Walk through your orange portal and then run back at the blue."

"What? Are you crazy?"

She gave me a wretched smirk. "Maybe."

"Ugh. Fine. I already fell about three kilometers today, so what could be worse..." I back stepped through my set of portals to find myself back where I started. I reared up, then charged out at the blue portal, hoping for the best, but expecting the worst. It wasn't until i was already past the first portal and careening towards the second portal that I actually figured out what was going on. I was about to fall down into the second set of portals with forward momentum, so that when I come out of the final portal, I would be flying diagonally upwards, onto a nearby ledge, which should have been unreachable. Fucking genius. But if I had to think like this to survive down here, I might be screwed.

The thought of it happening passed quite slowly as I had my 'moment of dawning comprehension', but the real thing happened really fast. I dropped into the second portal, flinging myself upwards, and making me land with a crash on the ledge twenty feet above where I was just a second before. "Holy shit! Genius!"

"I know I am." Celestia said with a smirk, just before repeating my actions that got me up here. When we were both up on the catwalk, I chilled out enough to realize what Celestia didn't do. Fly. I feared the worst.

"Um, Celestia?"

"Yes?"

"Why didn't you just fly up here?"

"This is why." She lifted up her wing slightly to show me that it had been surgically clamped to her side. I cringed after I realized what I was looking at.

"Does it hurt?"

"Only if I try to fly. I can sort of glide by doing this," And with saying that, she extended her wings a couple of decimeters away from her body. "But it isn't very effective."

"Well, at least you have that. But now what?"

She stared at me like I had lobsters crawling out of my ears. "Well, dummy, we climb up the stairs. What else would we do?"

I looked up to find that the ledge was attached to a large concrete pillar, which had a staircase spiraling up it for about a hundred meters. And on top of that, was perched a large geodesic sphere, supported by large steel beams connected to the sides of the void.. This one about two hundred meters wide... Dammit, why must everything here be so massive? "Holy shit. That's scary."

"Well, it was built seventy years ago. What did you expect?"

"To be honest, a cube. Not a sphere. But... Why a sphere?"

She laughed and gave me a dumb look. "How the hell should I know? Luna built this, not me!"

That's right... I still couldn't get over that. Well, I could to the point where it didn't disrupt my life, just the thought part of it. We started walking up the stairs side by side, talking pretty much the entire way.

"So where are we headed through to get up?"

"I thought I already told you. The old cooperative testing courses. They are dangerous, but it is the only way up."

"How many other testing courses are there?"

"Thousands more. And each one of those has around five to thirty testing chambers in them. Throw in a couple thousand offices, a few control centers, about a hundred pump stations, and a command module, and you can get an idea of how massive this place really is. It was originally built in the site of a salt mine... Started in the late forties as a harmless science experimenting ground. It wasn't until several ponies disappeared down here that investigation started to take place. Sure enough, the investigators disappeared, followed by the ponies that went looking for them. Soon enough, Aperture Sciences, as it came to be known, was unstoppable. They were both the cause and solution to most of the problems in Equestria. And all along, I knew that Luna was behind all of this, but I couldn't prove it. And sure enough, the second I find out where all of those disappearances were taking place, I disappeared too."

"True story?"

"True story. All of it."

Now, usually I'd be exhausted by now from climbing twenty stories up, but whatever Luna did to the air in here really messed me up. And I can't tell if that's in a good way or not... Here, I can lay it out to you:

Pros: Never hungry, thirsty, or tired.

Cons: I feel sick beyond measure, and I have absolutely no idea how fast time really is passing, so I don't know how long I've been down here. It could be anywhere between twenty minutes and two hours...

I still knew that I needed to get out of here, so I trudged past my sickness to continue upwards.

"Celestia?"

"Yah."

"Where exactly are we?"

"Directly beneath Canterlot. The entire city is built directly above this pit... And as I would guess, if you were lucky enough to get on an elevator that moved up, then you would end right up in the Canterlot sewer system. Climb up another twenty feet? Canterlot."

"So this pit was dug before Canterlot was actually founded?"

"Yeah."

"Then what about Hearth's Warming Eve and the meaning of all of that?"

"It's an odd story. The original Canterlot was actually in the Everfree Forest. You know the castle ruins up there?"

"Who doesn't? That site is pretty much infamous by now."

"Well, the supposedly infamous incident of Luna and the Nightmare has an untold side: Luna never went to the moon. Nightmare moon is just the Nightmare trying to imitate Luna, and the Nightmare was the only one sent to the moon."

"Whaaat?"

"Yeah, sounds crazy, I know. There was a war between us, but we won and banished it to the moon. Once we won, we were forced to relocate our civilization to somewhere else. Unfortunately, our best land for settling was already taken up by the salt mine that we're in now, which was only used for resources back then. About thousand years later, the modern-day Canterlot palace was created, and when we had to expand, we just closed up the salt mine and built over it. Odd decision, I know, but it was the best at the time. Besides, nopony expected the new Canterlot to last longer than a few hundred years anyway. A while later, the Nightmare returned, trying to take Luna's place again, but this time she was stopped before any damage was done. Luna went out of her secret rule and back to the public, and you basically have what happened about seventy years ago. However, then she went psychotic for real, and here we are now."

"Facinating..." Although I couldn't think of anything else to say afterwards, I still meant it.

By now we were almost to the top of the tower and into the 'enrichment sphere' (as the signs pointing up said), so I stopped to take a look at the view from above. And to be honest, it looked exactly like a book that I vaguely remember reading... The City of Ember. Basically a sci-fi novel about citizens of an underground city. Looking back down at the glowing fires and the desolated rubble that inhabited the bottom of this 'facility', a question came into my mind. "Celestia, who originally dug out this pit?"

"It was an odd group of settlers who started it long go. The descendents of the original settlers, actually."

Well, guess what? We're here! The precariously perched sphere suspended in the bizarre pit. Of course, it looked a lot larger up close, but when we rounded the top of the stairs that lead to a ladder going in the sphere, we were in for a surprise. As I climbed up the ladder and poked my head into another dark and grimy room, I took account of my surroundings. This room was a bizarre cylinder, filled with all sorts of trash and leaky pipes. I stepped fully into the room. Smelled mustier than down below, but that didn't make a big difference to me.

Towards the back of the room was a dark sign in bold forest font, reading 'TO TESTING'. Next to it was an arrow pointing to an open doorway that led to a corridor. I shuddered at the sight, but I could guess that it was the only way through, so I continued.

Celestia followed not too far behind me, so by the time I could get a good idea of the surrounding area, she was already in with me. She prodded my flank with her horn. "Oh, come on. Get going."

"Okay, fine." I stammered my way through the room to the corridor. And to be honest, the condition in there wasn't all that different. Still nasty. When we reached the end of that, we ended up in a lobby that looked like something straight out of the Jetsons, but throw in some horror and a lot of time and you've got what we're dealing with here. Damp, degrading retro sofas, rotted coffee tables, even throw in some abandoned offices and busted TV's.

We were both alarmed to hear a male voice come on overhead on unseen speakers, which sounded familiar... This fuzzy memory thing was just becoming frustrating. "Hello fellow citizens of Equestria, and welcome to the Aperture Science Testing Facility. We have some great science adventures planned out for you today. If you were the ones to sign up for zombie response training, pick up a rifle and follow the black line. If you signed up for the cooperative portal training, grab a portal gun and follow the orange line. If you signed yourself up for harnessing magic for the Magic for Earth Ponies program, we have good news and bad news. The bad news is that program got postponed until we can figure out a way to stop fellow ponies with those bizarre spontanious combustions that I mentioned earlier. The good news is that we have a much better activity for you..." His speech went on for a while until I spoke to Celestia.

"Hey. Do you know who that is?" I looked over at her to find that she had a look of surprise on her face. "Celestia? You okay?"

"No. That was Prince Blueblood. I should have known he was behind this... What a bastard." Great, now she's mad and I don't know why.

And finally, more memory came back. I was relieved to know now more of where I lived (two story house on the southeast corner of 35th street and Kilmore Ave.) and who I was acquainted with. I still had a lot to uncover, but I didn't know what I could. At least I found out who Blueblood was: A snooty, stuck up stallion who's intent on everything was to have more of it than anypony else. So basically the stereotype of a rich kid, but one who should know better in the first place. And to make matters worse, he was royalty. It would only make sense for him to be part of the monopoly that was Aperture. At least it wasn't Luna, or else we would have had a huge problem on our hooves. All I can say at this point is that even though I've lived in Canterlot for all my life, I still haven't figured out the royal system yet. I mean, seriously... Two princesses, a prince, and no known king or queen? What.

After Celestia had a chance to cool her jets (literally, her wings had started to flare outwards in... rage, I suppose?), we followed the orange stripe of peeling paint that headed to our right and soon found ourselves in front of a rectangular, vault-like door. It was locked shut.

Celestia put down her portal gun. "This place must have been condemned... Here, let me try something. Stand back."

I stepped back and watched Celestia in awe as her horn started to glow red hot. She touched it to the door, and to my surprise, began melting away at the locked metal door. Soon enough, a circular pattern was beginning to take shape on the door in the form of melted iron. In about ten seconds flat a hole was carved large enough for us to walk through, leaving a massive hunk of metal to fall backwards and onto the damp carpet below with a loud 'BOOM!' And sure enough, we found ourselves in front of another ridiculously nasty corridor. This one we knew must have been untouched for at least a half of a century.

"Wow. I thought you couldn't use magic here..."

"Well, we can't use magic on other things, but we can on ourselves." That was a huge relief.

We waited for a while until the metal cooled enough to touch, then picked up our portal guns and made our way through. Celestia went in first, lighting the way with her horn. I followed, still not knowing what to expect. It felt as though we were still being watched, even without the presence of those bizarre security cameras. Almost like a horror movie, to be honest. Except I had nopony to tell me when to duck or not to enter a room. Then again, I never had that in the first place.

As we sludged our way through the cold, mildewed hall, I tried talking with Celestia to ease the impending doom that lingered in the air here. "Um, how does one test cooperatively?"

She caught on to what I was trying to do quickly and dead-ended the conversation. "You'll find out in about four seconds. Shut your trap."

And as she (sort of) promised, the hallway came to a stop and turned right, leading us into a tall, square room. Everything was still made of concrete, with the exception of two black metal tubes hanging downwards from the ceiling and a large section of the opposite wall was taken out to reveal a large, dark room. Blueblood's voice came back on. "Well, congratulations! You qualified to take place in our Cooperative Testing program. Remember to think with two sets of portals, and good luck on your science adventure. The testing will start in three... Two... One."

Floodlights filled the room with brightness, revealing a fairly simple obstacle course made entirely out of rusty steel and mossy, damp concrete. The room looked retro, while still holding a spacey, futuristic feel to it. Kind of weird. I liked it.

"Alrighty then. Where do we start?" I asked.

"I'm not entirely sure... But that doesn't mean we can't start looking for an answer." And with a dastardly smirk, she was on her way, surveying the test ahead. Her ambition towards this alarmed me, but that didn't stop me from following her lead for some reason.

I surveyed the concrete and metal room... Large, rectangular, and had a large gap in the middle that streched all the way to the left and right. Filled with a vile green sludge, so probably deadly. At the other end of the gap was a doorway to another hallway, perhaps leading to another test chamber. In one corner to the left, there was a large, open faced metal box with a concrete ceiling and floor, with a horizontal incandescent particle field wedged in between. Like it was meant to have a portal on top and bottom, perhaps generating confined speed... "Hey, Celestia. We can start here." I nudged my nose in the direction of the box thing while Celestia took note.

"Okay, I'm trusting you know what the particle field does, right?"

"Zaps cubes. Keeps you. That's all I know. Something else?"

"Yes. If a portal gun passes through, both portals that came from that gun will dissipate. So this thing here, the infinite loop, has to be used by the pony who doesn't shoot the portals. So, stand in there."

"Are you sure this will work?"

"HAHA! I HAVE NO IDEA! Just kidding, of course this will work." Her voice still hinted doubt, even though her humor was trying to add a lighter touch to the situation.

I stepped forward and into the box thing as she shot a red portal directly above me, then the purple one directly below me. One split second after I was painfully aware of gravity's existence, and I was falling. It was a really bizarre sensation, pretty much like the floor you were standing on instantly dissipate. Luckily, I was half expecting it, so I didn't have a heart attack. But it still was frightening, seeing multiple Celestias whizzing upwards as I flew downwards as I was getting shocked about three times a second by the (still bizarre) particle field.

"Now what?!" I yelled at her through the wind.

"Hold on a second." She pondered for a second, then right as my speed was somewhere beyond 200 kilometers an hour, she aimed her portal gun upwards. I had no idea what she was doing until it was too late to stop what she was trying to: Her portal gun momentarily glowed bright red, then shot out a streaking beam of energy, aimed high above the entrance to the room. And sure enough, my next lap through the portal sent me soaring downwards, but now pointed towards the other end of the room. The portal gun nearly slipped out of my concentration, this thing took me by surprise! I quickly righted myself by flailing my hooves in midair, then braced for impact as I heard a familiar 'THOCK' against the floor. And before I knew it, I was on the cold metal floor on the opposite side of the room!

"Holy bit, where did you learn that?" I exclaimed.

"Self taught. Everyone down here must be, the announcements don't give any clues."

"So now what?"

"Look for a concrete slab to shoot a portal on. Then shoot one back here so I can get over there."

"Can do!" I walked into the hallway at the end of the room, found a portal-compatible surface directly to my left at another turn, and soon Celestia and I were walking side by side again to the next test.

"Well, now. That wasn't so bad, now was it?"

My legs were shaky, I felt sick, and I could hardly breath. I rolled my eyes and smartassed her. "Sure."

"Good. Let's continue."

We were already in the second bend on the steel corridor, so all we had to do to get to the next chamber was turn to our left. As we did so, we were met by a shock. Not literally, thank God, but still... The entire next room was gone. We could tell because the faint lighting nearby hinted jagged metal edges around the end of the hall, but we still couldn't tell what was ahead. We stepped forwards to find out. We must have triggered some sort of motion sensor, because the voice of Blueblood came back on.

"WelcdvnnhZZZZCKKM..." A long, awkward pause followed. "Well, it would appear as though the first test wasn't a problem for you, so let's get you a little bit harder one." The familiar shine of floodlights suddenly filled the room, revealing what appeared to not be a testing chamber. Rather, a void. Again. This one in the shape of a giant sphere. The entire bottom of the sphere was flooded with the green sludge to about ten meters, looking like the stuff in the last room. And by the looks of it, there could be a connection between the two. The sphere looked as though it was split in half by a large concrete slab, and we were on the left side. So, basically, we were looking at the shell of the large sphere we were in. I guess I didn't realize exactly how big the ladder into here was, because we were pretty high up. About thirty meters, if I had to guess. But by the looks of things, the space between portal-compatible surfaces hinted that escape was either very difficult, or impossible. But there were some oddly oriented concrete pillars and slabs in the sludge, so that provided some hope. Naturally, I had to look to Celestia for a way out.

"Any ideas? Preferably ones that will allow us to live?" I asked anxiously.

"I got one. Let's do this... See that ledge over there?" She pointed to her right to show me an overhang of steel on the dividing wall.

"Yes... What about it?"

"Shoot a portal on the sphere forward of that, then shoot a sideways one on the platform in the sludge."

I did what she told me, even though I didn't trust what she was doing at all.

She jumped. I'm not sure if you know what level of insecurity I'm dealing with here, but when you're dealing with the two-thousand-year-old former leader of Equestria, shit gets real.

I leaned over the edge to see what had happened to her. And to my (HUGE) relief, she had already shot a red portal on a platform directly below her and had shot the other on the right side of a large, vertical pillar to the left, hopefully flinging her to the platform in the middle of everything, ultimately catapulting herself to a busted ledge on the large concrete wall to the right. Eeyup, it's official. I'd never be able to do this on my own.

I looked back up to see Celestia fly through the first set of portals and over the sludge, and then go diagonally into the second to arc her way to the ledge, landing with an all-too-familiar 'CRASH'. But she was alive, so all was well.

"Well, what are you waiting for?" She yelled at me.