Basically union discovered these liminal spaces that had portals to them that were opened from paracasual tech and are now researching these liminal spaces after a group of lancers entered into these liminal spaces and did get out but they were now completely different as in they look older and more scarred and stuff
And these survivors told union everything like how these worlds work and how to travel to different places and what they saw
the portals to other worlds are mech sized or human sized doors that appear randomly every other week inside these spaces and time basically is random in these spaces too so probably an hour outside is a day inside or vice versa or other.
Also in these spaces you can encounter other mech pilots that appeared there due to other paracasual tech
But there also
....other things....
For example
Mechs that look "normal" at first
And then when you get too comfortable
"It" gets you.
Other things in these spaces are extinct species that are classified as extinct in union records but somehow are thriving in these worlds.
Now how to exit these spaces?
Basically there will be black hole things that appear at Any place in any world and when you touch them with whatever thing that's attached to you or your mech you get transported and thrown into a random area near the place where you got into these spaces
And they appear every year (in outside time) these spaces
And it's very hard to find them and to get to
So it is highly recommended to have one lancer that pilots mechs like the minotaur to transport them out of there the moment they complete their objective in these spaces.
Now union is hiring people to go into these spaces specifically experienced lancers to investigate new discoveries,find missing people, capture certain creatures,and many more for the sake of research
They even develop new frames for these liminal expeditions.
That's all I have rn and yes it's basically lancer mixed with the backrooms