Spoiler (click to show/hide):
Humanity was by no means a perfect harmonized species. All across the world there was conflicts, for a myriad of reasons. Some rational, others not. Some simple, others unbelievably complex. Nothing however unifies like a shared threat, so when three months ago when it was leaked from multiple government space agencies from many different countries that a colossal planetary sized object had entered the solar system and was on a projected intercept course with Earth? Well, suddenly spilling blood for minor religious differences or taking relatively small plots of land isn't so important anymore.
Information was constant. A firehouse of leaks and rumours and speculation that kept people relatively informed but also fairly confused all at once. Deep space observation wasn't exactly high fidelity imagery yet after all, so in the beginning all that was known was that something bigger then Earth entered the solar system. A rogue planet perhaps? Curious though it was projected to pass so close by to Earth however. A couple of weeks later though when it was learned that the object was not a planet at all but in fact a ring, and moving incredibly fast to boot? Well... did the world well and truly lose its collective marbles. This wasn't no ring around Saturn after all, but a very clearly artificial structure. Something that only became more and more cemented the closer it got.
When it eventually passed no one could've predicted what actually happened, because like the ring itself it just seemed impossible to rationally consider. It had passed around Earth, as if the planet were a basketball and the ring a basket, a basket with a mach larger surface area of Earth that is anyway. Might've been more accurate to say a soccer ball in a circular net given the actual difference in size. What had happened though, or at least, as far you knew, was that the ring had somehow... teleported an entire section of the US western seaboard onto it's surface. Just... bam! One second your looking at the shape of the ring passing in the sky, coming between you and the moon, then a blink later your looking up at Earth, a massive sapphire in the sky soon drifting away in the cosmic distance. What kind of technology or power could do such a thing?
In the end more then two thirds of California, nearly the entire southern half of Nevada, and decent chunk of Arizona, with literally anything and everyone there at the time was now on the ring. For a month at had been chaos as the transplanted sect of humanity ran through its natural panic, but then humans did what humans did best and started to adapt. They organized, took stock of their resources, banded together, assessed, and acted. After about another month of hard work, some basic utilities had been restored, though power was being rationed still pending... well, finding more resources. The supply chains for oil, natural gas deposits, and heavy water for nuclear cooling where still disrupted for the time being, to say the least.
With basic needs met at least though, the now lost sect of humanity you are apart of began to explore their surroundings. They seemed to have merged seamlessly to the Rings inner surface, the area wonderfully temperate, and their chunk of land now part of its western coast rather then North America's. The new area was... well, alien, but also shockingly similar to a lot of regular Earth life, but more then once do you encounter fantastical beasts, some fitting myths and legends and fantasy lore, others completely unique. There was other intelligent life as well, but they all seemed rather primitive and tribal, fitting to the level of a medieval kingdoms at best, though most were more tribal. Among it all, strange alien facilities presumably native to the ring world itself were scattered, freely accessible to boot. Though most were so beyond humanity scope of understanding that discerning their purpose, let alone how to use them, would be quite difficult...
Now this is were you come in. You had been a regular guy before all this, working a simple job 9-5 tech job in silicon valley. Now though you were a part of a exploration team that joined Californian national guard units by exploring these strange alien facilities, some of which were starting to pop up in the transplanted American land mass! Your team had gone into one somewhere right at the crux of the three transported States, and like normal, or at least what you now considered normal, not much happened. It seemed to be all silvery walls and large open rooms. Some of them might have equipment in it, but it was so similar to walls it was hard to tell, and no amount of poking and prodding ever seemed to do anything? And cutting? Forget it. Eventually however you turned a corner at an intersection and saw a blue glowing light... You turned to inform your friends, but the way back had shut seamlessly. You went forward, and came into contact with the apparent AI controller of this massive ring world. It had wanted something from you, needed you for a purpose... What was it though? Did you agree? You remember being excited, but perhaps that was due to the fact that you had made a big discovery.
You'd hopefully find out soon enough. Consciousness suddenly explodes within your being as you come to with a sudden gasp, breath coming in quick pants as if you'd been holding it or underwater. You open your eyes and discover that makes sense when you appear to be in some kind of tank, the thick greenish liquid in it draining away. It seems to be made of glass, allowing you to see out and a plain silvery room your in. Just outside the tank however is a what looks to be a simple cylinder, a glowing blue sphere projected at the top. A terminal for the rings AI, waiting for you perhaps? Looking back to yourself though... you get quite the shocked when you suddenly find yourself staring at a generous pair of tits attached to your own chest as the green liquid drains past them. The more it drains away as well, the more differences you notice... you were female!