This pony was fast, I'll give her that.
Los Pegasus organizes air traffic into three layers, the first and closest is for local traffic, the second is higher and for inter-neighborhood fliers, and the third is for those leaving and entering the city. This filly was smart enough to stay in the first layer, keeping low to the clouds so as not to risk a collision. She was flying far above the speed limit, and in the wrong direction, causing ponies to drop or rise to avoid her and prevent a crash. This also meant that the traffic opened up as I traveled in her wake, I didn't have to dart around other fliers while she did, allowing me to slowly catch up to her.
She shot a glance back over her shoulder towards me, her tiny wings flapping four times faster than mine to make up for her lack of size. As she noticed I was flying in a clear area, she dove right down to cloud-level and skimmed along the streets, only a few centimeters from the floor. I dove to match.
Now this was downright dangerous, ponies were crossing between buildings and talking to one another. Flying in this obstacle course could lead to a lethal crash, yet Rainbow shot expertly between all comers, rising to avoid a business pony who, terrified at the close encounter, threw his suitcase full of papers up into the air. I banked and narrowly avoided him, catching one of his documents in my face and pulling it off as I saw Rainbow bank tightly around a corner.
I took the corner wide, and it was a good thing too, as she had purposefully taken this corner hard so that I would crash into a barber's shop sign. She shot another look over her shoulder to see me still pursuing, and banked into an alleyway across the street.
"Wait, stop, come back!" I shouted at her as I moved to follow. She either didn't hear me, or ignored me, hard to say given all the noise the wind was causing. The alleyway had an overhang in it, as I shot by I lost sight of Rainbow for a moment before it occurred to me to look behind me. Sure enough, she had been hiding on the overhang and had doubled back behind me. She knew the city very well, I was just a guest here and keeping up was getting more and more difficult.
Fortunately, Rainbow had thought she lost me and soared up into the second traffic layer. I took the opportunity to get closer while flying directly under her, she didn't look down, only back, to be sure she wasn't followed. Her pace eased and she slowed down slightly, making the chase easier until I could pull into a climb and grab her from below.
"Hey, watch it, ya weirdo!" came the yell of some pony who I darted past. I hadn't been watching where I was going, I was looking up at Rainbow. The commotion caused her to look down and recognize me, then speed up as she took advantage of her height.
It took great effort to keep pace with my height disadvantage, Rainbow had left the neighborhood and was heading to another cloud at a lower level where I could make out a complex of about six buildings. Judging by the signs, they were restaurants of some sort. I was now about 150 meters behind her, and she could dive to gain speed. In a more narrow environment, should could lose me easily, but as long as she stayed in the open air it'd be hard to shake me.
Rainbow seemed to realize this, taking another look over her shoulder before diving towards the restaurant complex. The alleys between the buildings were too narrow for me to fly through with my larger wingspan, while she could navigate just fine, this had been her plan. As she darted into the narrow gap, a griffon with a garbage bag exited one of the buildings through the back. She frightened the griffon and he tossed his bag into the air, scattering its contents all over.
I couldn't follow Rainbow through the alley, but I had an idea. I instead went to the center point of the six buildings, and watched closely to try to spot her. The angles of the buildings made it difficult to see anything in the alleys except what was directly below me, though Rainbow could probably see me just fine. As I hovered and waited for her to expose herself again, I made a show of looking around while I was quietly raising my own height, one flap at a time. When Rainbow would eventually have to leave one of the alleys, I'd have a big height advantage and could dive to catch up.
A minute passed. I could hear the Griffon swearing to himself as he picked up the garbage and put it in the dumpster. The area became quiet, very still, I couldn't hear anypony moving around. I keep sweeping my sight to cover the exits.
At last Rainbow made her move, waiting until I was looking the other way before darting out the alley farthest from me. Though she was fast, I put myself into a steep dive and closed the distance very quickly. Her acceleration was incredible, a born athlete who was able to keep ahead of me even with the dive advantage. I closed the gap to 30, 20, 10 meters. Rainbow, from the corner of her eye, saw me getting closer and entered into a dive, a streak of rainbow behind her as she plowed through a nearby cloud and scattered water droplets everywhere. I angled myself down to follow, still very close to her tail.
I had a plan, of sorts. Rainbow couldn't see my still-invisible horn, once I got close enough I could use my telekinesis to grab her. I'd need to be right on her tail to do it, since a miscalculation could leave her with a snapped spine or a broken leg if I failed to catch her whole body at once. She could easily wiggle out of a telekinetic grab, but I was banking on the sheer surprise of it to keep her still until I could pin her with my body. Once my weight was on top of her, she'd be unable to escape.
Rainbow pitched her dive into a near-vertical angle, shooting beneath the lowest layer of the city and into the open sky below. It was several kilometers of empty air around us in every direction, she no longer wanted to hide but simply out-fly me. As I was so close to her, she picked up speed and began leaving a turbulent wake behind her. This air was bumpy and uneven, one bad shock wave to my chest and I'd have to break off my pursuit. Once again, Rainbow had proven herself to be a master of aerial maneuvering.
Fortunately, she still didn't know about my magic. With no witnesses within sight, I cast a filtration spell in front of me, just like I had learned when I was straining spaghetti with mom when I was a filly. The spell filtered out the air, making breathing more difficult but also neutralizing the turbulence and allow me to gain even more speed with less air resistance.
Rainbow shot another glance over he shoulder, and saw me with a pink-colored filter flying in front of me. Her eyes widened as she saw my horn, now fully visible and casting a magic spell. I could not tell if she was able to piece together just who was chasing her at this point, if she did, she did not stop the dive. That, or she could not stop it.
She faced forwards again, the air ahead of her had started to build up a sonic bubble on it. We were now dangerously close to the sound barrier, and any thoughts of catching Rainbow were quickly receding as I now needed to find a way to avoid getting torn apart by a sonic boom if we went any faster. At this speed, even a slight bank in any direction, even the tiniest miscalculation, would cause the air to rumble and send all the energy stored in the sound back into us and send us in every direction at once.
This was high-school level physics, I doubted if Rainbow was even fully aware of the danger surrounding us as we approached the stress envelope. The air around us thickened and began to vibrate audibly to me, the envelope was not quite symmetrical due to a slight difference in orientation between Rainbow and I. The resulting disturbance was slowly building up, I could see a small vortex appearing to the right and just behind Rainbow's tail.
The choice now was to catch Rainbow, or to save her. There was no chance of doing both, if I grabbed her at this point the resulting shock wave would doubtless break something, in her or me, both were unacceptable. The choice had been made for me, I needed to either stop Rainbow or neutralize the vortex which was building up.
Calling out to her would be pointless, as the sound would take several seconds to catch up to her since we were so close to the barrier. I instead banked just slightly to the right, beating my wings once. The air offset caused the vortex to stop spinning clockwise and start spinning counterclockwise, and all the force from the switch rocketed out in every direction. I took the hit full in the chest, my magic filter stopping it enough that I didn't seriously hurt myself, but my pursuit was done. The airblast caused me to tumble over and over for several seconds until I stabilized myself and got my bearings again.
I looked around, trying to see Rainbow. I checked down first, in case the blast had knocked her out, but I could see nothing towards the ground. After a few seconds, a rumbling from somewhere above me drew my attention upwards just in time to see a rainbow streak shooting back towards the city at incredible speed. By the time I would be able to make it back up that high, Rainbow would be long gone. I wondered whether or not she realized that I had just saved her from herself, why she had been so eager to run from me despite the doctors reporting her as having the least severe symptoms. Something wasn't adding up.
I recast the cloaking spell as I made my way back up to the city, taking my time. I was exhausted, and more to the point, mildly confused. I had gone from terrified of any extended flying to an expert in a short time, clearly one of the many unremembered memories I had had taken over and given me the skills I needed. Unlike last time, I hadn't re-experienced it, it had just come to me and felt natural, perhaps because I had no time, not even a millisecond, to relive the old days.
In any case, I had already had a long day and angled my way back to what was home, for now. When I arrived the twins had fixed the place some more, some crude windows had been kicked into the walls. Squeaky was doing something to the collapsed roof as I swooped through the gap and landed on the floor, perhaps a little too hard, and stumbled. I landed face-first on the cloud floor, which wasn't so bad compared to the hardwood at my Canterlot home, or the stone in the palace.
"Wow, you look like hell. What happened?" Squeaky asked me as she hopped off the roof and landed near me.
"Just a long day is all," I said, prying my head out of the clouds and standing up.
Squeaky gave me a long stare as I heard Minty come out of the hallway behind me.
"Wow, you look like hell, what -" Minty started to say as Squeaky switched her glare to her twin sister.
I turned around to face Minty, "Long day. What's for dinner?" I asked.
"How about some paper towels covered in soap? Because that's all we have," she said, tossing down a rag she had been using to scrub. "Laundry room is mostly disinfected."
"Didn't we clean that out last night?" I asked.
"Yeah, but it came back. So, I'm pouring alcohol all over every surface to kill everything. Everything." she said.
Squeaky ambled towards the kitchen and opened up the new fridge she had installed.
"Take a look, we have nothing, nothing, and nothing," she said, showing me all the fantastic nothing they had bought that day.
"No time for groceries I see," I said, "Want to go out again? It's on me."
I decided to take us back over to the cluster of six restaurants that Rainbow had tried to lose me at earlier today, hoping to catch a glimpse of her. She had lured me there purposefully because she knew the area, which gave a decent chance of running into her again, especially given how easy it would be to spot a mane like hers. Unfortunately, there was no trace of her, so we settled for one of the sandwich bars on the opposite side from where that Griffon had been taking out the trash. Last thing I needed was a confrontation.
The twins had decided that whatever I was doing was no longer preferable to fixing up the house, though they didn't ask me for many details. The look of exhaustion was all the answer they needed. Though I was too tired to go on patrol that night, I did it anyway, keeping myself on the clouds and wandering through the streets. I didn't find anypony lashing out and my instincts were quiet, so I went back home after only a few hours and went to bed. Since I had gotten distracted, I would need to go see patient twenty-one tomorrow, and I suspected it was going to be much more than a casual visitation, I would need all the strength I could muster.