The Strange and Secret Life of Lumen Sky

-Twilight-

At the bottom of the stairs was the last door and when the door opened a more welcoming breeze flowed out. It smelled not of a cave, but a home in which nopony had been in for a while. We walked out into the large room that had several hallways coming off of it. At the end of each hall there was a lab specified for a specific study.

"Here is the chemistry lab, physics lab, and the electronics lab." He said while gesturing towards the respective hall. "These are the most used labs in the entire complex."

"Where is the Jet Propulsion and Flight Center," I asked eyeing the beaker of purple liquid that had followed us the entire way down here.

"Oh, that is right over here," he said leading the way to a small prep room.

Once in, he put a lab coat on and tossed me one. The peculiar thing was how the sleeves came all the way down the beginning of my hooves, it was also unusually thick. He walked to a counter sitting in the corner where two gloves that were very thick and blocky; they looked very metallic but bended very fluidly as he put them on. The surface shimmered as it smoothed out to the shape of his hooves.

"Well then, let's press on," he bubbled while walking to a very small room sealed on the other side with a thick looking door. We walked in and the door shut behind us and the smell of fresh air filled the room. There were two lights beside each door and both had turned from red to green. The door opened and we walked out into a very large tunnel that had extremely high ceilings and the walls sloped up to meet the apex of the roof to make the tunnel shaped like semi-circle. It went on for maybe a mile or two and was filled with several large cylindrical objects covered in tubes and other mechanical and electrical components. There was a small car with seats and controls that Nathan was walking towards and it sat on a track that ran the length of the tunnel.

"Well, if this isn't enough for you than your mind will be blown with this." He got in and started typing on the control panel and the cart started hurtling down the track. After a while we passed by a very long window behind which a very large steel torus sat.

"What is that," I said looking at the object.

"Oh that, that's a particle accelerator. I haven't tested it yet, I am still waiting for the right time. Maybe after your friends can come down here I might turn it on," Nathan said with a small smirk. I could tell he wanted to make a small show of using this dangerous and interesting device.

At the end of the ride we had reached the end of the tunnel where a very large concrete wall stood and a very large door stood as well. We got off the cart and the door slid open revealing another cavernous room stood but this time, filled with the smell of motor oil, rubber, a slightly potent smell, and the scent of the plains. At one end of the room a large black object stood with a small glass dome stretched from the end of a shiny black cone with a large pole that tapered down to a point at the end. It had two very large, almost sharp, wings protruding from the side and had two smaller ones on the back that were not as sharp as the big ones and were sticking up into the air; they also had smaller rectangles on their back end. Situated on the back were two large black open-ended cylinders coming several feet out the back. The sleek figure stood on three large black wheels suspended on large white supports and looked to be lowered and raised by some form of hydraulics.

"What is that," I finally said.

"That," Nathan said pointing at the figure," that is Equestria's first plane. It seats two, can accelerate at almost one G, and is light enough to be pulled by a single pony. That is not what we are here for though, we are here for another prototype." He walked over to the large steel doors that spanned almost the entire length of the tunnel and opened them with a deafening roar, to reveal a very long stretch of pavement and a very large field. Several small buildings rested just off the road and he was going towards the closest one.

"Is that the technology that Equestira would war over if they had it?"

"Yes, everything in the labs we have passed were locked up from the rest of the world to keep the peace."

"Very interesting. Oh, how far away from the city are we," I said, completely boggled by the time we have been underground.

"We are about a mile out," Nathan called as he strode towards the small cuboid. There were two very large doors at each end of the building and once they were open another large mechanical cylinder sat inside.

"That is the prototype of the fastest jet engine ever made. It has over seventy-two thousand pounds of thrust and has a very powerful afterburner. This is the Mark II and its predecessor, well, exploded, and gave me this," he turned and lifted his mane to show a still healing scar no longer than just a few inches that ran almost perpendicular to his spine.

"Wow. Have you tested this yet," I said, fearing another explosion.

"Well, yes and no," he said while attaching cables to the engine.

"What do you mean no?"

"I haven't tested the afterburner yet."

"Mmmmh, that's what I thought." I said, if I had glasses on I would be looking at him over them. "You haven't told me what that purple stuff is," I said, still wondering why he was carrying that beaker around for.

"That is a high density fuel for a rocket designed to yield a higher thrust than conventional fuels. The only drawback is that it is hideously toxic and will go through rubber."

"Is it that new stuff the pegasi are working on called...called..."

"Dimethylmercury?"

"Yes. Why do you have that?" I said, wondering what he is using that for when the health hazards are that high. This pony is completely insane, I thought. No he's not, it's just that he is, different and just a little on the crazy side.

"It was an experiment and this is the last of it. I sealed it up to keep ponies from being poisoned. The glass is shatterproof and will absorb the contents if broken so I can burn it. It is merely just a sample for reference and a keepsake now."

"Why have you been carrying it around then?"

"I forgot it was there."

"Yeah right."

"Really, can we test this before the royal guard comes and take me for supposedly kidnapping the princess?" He was starting to get a little edgy.

"Fine but, please don't blow anything up."

"Okay." He started hooking up many more cables and sensors to the engine. When he was done he led me to a room with a window facing the engine. He inserted a key into the dashboard and turned it, lighting up dials and making displays light up and displayed many zeros and dashes.

"Here put these on," he said, handing me a pair of headphones. He put his headphones on and flipped the cover on a large button that was glowing red and pressed it. The engine roared to life and dials started to move. He throttled the engine up and a large cloud of mist exploded out the end of the hangar. After the engine reached its full speed Nathan flipped a switch and the dials moved more towards their fullest. He started throttling the afterburner up and the mist came again and the grass outside the door was flailing violently. As the afterburner reached its fullest power, the flaps on the back started closing and a blue jet of fire started extending out the back and from the flame came a jet of pure heat and in that jet diamond shapes formed and Nathan's face lit up as he smiled revealing braces and strange enough, short fangs. As the engine roared on the side became slightly red and the engine started sliding forward as cracks appeared in the concrete floor. His face fell and he started running magic and his hooves over the control panel, I could have sworn that the gloves he was wearing were flexing like fingers. The engine lurched forwards several inches and he hit a large red plunger labeled, Emergency Shut Off. The engine settled back down and the sound stopped as a paper flowed from a printer sitting under the dashboard. Nathan took his headphones off and I did the same.

"Well, that was very interesting. I can't believe how much thrust that put out!" He said as he jumped around the room.

"What were those shapes in the exhaust," I asked, still in a daze after what happened. He grinned, showing his braces and short fangs again.

"That was the exhaust exceeding the speed of sound."

"Does that mean..."

"Yes, that engine can propel my jet to a sonic rainboom."

"That would be a huge achievement for a wingless pony," I said as I tried to calm my nerves, having only seeing very few sonic rainbooms in my life.

"I know but, it still needs testing," he said, almost instantly coming of his hype.

"So if Equestria ever got this from you, then there will be wars?"

"Most likely. That is why I haven't told very many ponies about this. But, I feel that I can trust your friends, like a small tugging."

"Really," I said raising an eyebrow.

"Really." I just looked at him and we started back to the hangar.

The next five minutes we talked about who we could introduce to him. We walked back to the store talking about how my friends would react to this. We eventually decided to get him to meet Rainbow Dash because he might get along with her better than my other friends. When we reached the store he let me take the lab coat and sent me back to my castle almost two hours after I walked into the store expecting to get just one thing.