It sounds like you're replying to my post, but you can't be, because I made it pretty crystal clear that this wasn't a case of "find no matter what you do" but rather "find it after a very well thought out bit of role playing, and a bunch of well thought out player choices, just not where I expected them to look".
If I take the time to outline an example clearly, it's always nice to have people read it before they tell me I'm wrong.
Sure, and "shadow-play world"s are awesome.
In a "concrete world", you can add to the world. A different hint connecting things can be there.
(This is the difference between moving something and filling in blank spots on the map.)
Or, you can say "nope, not there". But again, in a 3 clue system (where important clues in turn have 3 clues to them), there
must be more than one way to solve the problem, and they are dangled in front of the players,
and there are plans for what happens if the players miss them all.
Dungeon World's fronts are something I'm still trying to crib for D&D.
You set up Fronts (campaign and adventure fronts). In the Fronts, you create Dangers, each of which has an Impending Doom. Coming up to the impending doom build some Grim Portents. Write some Stakes (interesting questions that the resolution of the front will answer).
The Front/Dangers/Dooms/Portents basically describe the things that will happen if the PCs do nothing. The Portents are the clues that the Doom is coming (a Doom is some (bad) change to the campaign world that is irreversible that the PCs probably want to stop). Dungeon World has mechanics for when the DM is permitted to trigger a Grim Portent (it has lots of DM mechanics).
Front: Demonic Conquest
Danger: Gnoll Horde
Doom: Region is overrun by gnolls, all kingdoms and cities destroyed
Grim Portents:
- Trade is interrupted
- Town A is raided
- Legion moves to defend pass
- Legion falls
- Castle B falls
- Mass refugees
- Capital falls
Danger: Necromancer
Doom: The Dead Walk
- Library destroyed
- Researcher looks for help
- Undead spawn
- Forest falls silent
- Dracolich sighting
- Artifact stolen
- King becomes Death Knight
Danger: The Chosen One
Doom: Demon Incarnate
etc.