Find your tribe in a Sea of Creativity
So we know that the first scene of TKEM is Lee Lim being interrogated by Tae Eul and Shin Jae.
He doesn't know them and it's all bloody (with his brother's blood). So what I think is that Lee Gon sent his uncle straight to the future after saving himself again. We also know that Lee Lim can't face charges in the Kingdom because the people from there can't know about the portal and the other world.
Then, we see Shin Jae holding his documents from the Kingdom:
And he doesn't seem confused about the symbol, which means he knows where it came from.
Tae Eul also says precisely that Lee Lim killed his brother, she's not even asking, just saying, because she already knows. And some may say that it's because he's drenched in blood, but I think she's the kind of person that would ask instead of accusing.
I can only come up with this: Lee Gon is working with Shin Jae and Tae Eul from "behind the scenes".