Had a quick thought... bear with me
1) "Core of the problem" could mean core world(s)? (bubble or even just SOL)
2) A new planetary body suddenly appeared in the SOL system that as far as I know doesn't exist IRL
3) That new planet is called "Persephone" which has obvious and numerous tie-ins with the Rift Mystery lore etc..
4) we have the knowledge that we have missed a clue(s) somewhere along the way...
I'm thinking a thorough survey should be done on the planetary body, either to find something, or eliminate it once and for all
At least that way we will either A: find another clue or B: Be sure its irrelevant and move on...
Thoughts?
EDIT: Sorry for proposing yet ANOTHER planetary survey... I'm not going to make any friends with this idea am I?