Here’s a different take on the alien invasion trope:
The world is going to shit: overpopulation, deforestation, pollution, global warming, everything. The only question is if we’ll kill ourselves off before we kill the planet out from under us. Then one day ships appear in the skies all over the world- not just America and countries with trendy landmarks, but EVERYWHERE. Efforts are made to stop the “attackers” but humanity is still rounded up and carted off to some strange alien facility.
Food (of a sort) and shelter are provided, but no answers are forthcoming because humanity’s captors don’t bother talking to us. Maybe select individuals are taken off for testing, but they all come back in more or less the same condition they were found, except maybe with immuno-boosters or a few troubling terminal diseases cleared up. There’s massive speculation about what’s going on and probably religions are formed based on various beliefs about what the aliens are doing with us, but no one knows for sure.
This goes on for years (or longer) and then one day everyone is rounded up again and taken back to Earth. Everything is exactly how we left it (except maybe dustier and overgrown) except now there’s no pollution, the ice caps have been repaired, global temps stabilized, ozone holes patched, everything. There are more forests, more crops, and maybe a few critical species (like bees) have been given a population boost. There probably isn’t a lot of thought to where people get dumped so a lot of folks end up in the wrong countries and whatnot, but eventually we sort ourselves back out and either make our way back home or settle down where we are. In a world that’s a little better than the one we left.
And that’s how humanity finds out they’re just an alien terrarium and the owners have stopped by to clean the tank.
me explaining underwear to aliens: we have smaller, secret pants that we wear under our normal pants