To give some context first: My party of three will eventually arrive in a town where they will meet with a representativ of a big organization that spans the continent. There is a black fog on the continent that drives animals crazy, summons monsters and curses, if not outright killing them, human.

This organization is supposed to tell them some lore about what exactly is happening and how to drive back the fog and eventually either seal or defeat the big bad.

Here is where I need some help: I want the group go search for multiple parts of a relic that can make the fog disappear if it is put together. The problem is I don't know what would be a good relic and what the parts would look like and the follow up problem would be why can the organization give some pointers where the parts are but can't get them themselves?

If any information is missing or if anything is unclear feel free to ask.

Tl;dr: What would be a good ancient relic/ how would parts of this relic look like and why can't an organization that spans the continent not get the parts themself?