As shown in both the post-Ep3 preview of Ep4, and the web promo: all of a sudden, both tribes are climbing over top of one another to hunt for hidden idols in camp. Does someone find one? Yes.

    As far as spoilers go, at least one idol is found (and used) pre-jury: for the Heroes tribe, according to both SurvivorsUnite and survivrcuz, Tom apparently comes into possession of one (presumably by finding it). Since he uses it in this episode, this must happen either before this episode, or during it.

Scrambling for idols vidcaps: click to view larger picture
CBS subtly hints at the number of hidden idols	Both tribes looking (including reversed Cirie!)
The lesson is: never try	Oh wait, it's just Danielle. Never mind.
Amanda has the right idea, it would seem	Cirie apparently believes seeing is finding
Poor James. Nobody is chasing him.	Wait, Tom and Amanda are?

   Since both tribes are looking for idols, it's unclear what the mechanism for releasing the clues/ announcing they're hidden really is. Possibly the RC winner gets clues to the location (and Probst announces this, alerting the losing tribe that they have one too). The ads make it look like both tribes are reading treemail to that effect, but from the beard growth (particularly Colby and Coach), those shots look recycled from past episodes. Regardless, both tribes search, and at least one tribe finds. Good enough.

Update: While CBS has hyped this part of the episode at the expense of the challenges, spoilers at Sucks have not been napping, either. It appears both tribes find hidden idols early on, and we'd guess that both will probably be shown in this episode. SurvivorsUnite says Russell finds one (circa) here.