Let them wander. Sometimes, searches produce no results. This is not the best option, nor should it be the first thing you do, because players get frustrated when the clues are too subtle or not clear enough. Tread carefully here, there be empty gaming tables in this part of the map. If they are to come up empty-handed, make sure it’s presented to a quick way and may be accompanied with clues to steer them back on course.
To steer back on course try these tips:
1. A few red herrings
2. Be very careful of balance…not to subtle “FLY YOU FOOLS!”….they never got it.
3. Never metagame plot points.
4. Not to obvious... “Is that a blade in your pocket or is that…”
5. If the players get the hint before you gave it, let them run with it, and leave the hint out.
6. Decide to take a break. If you are looking for a place to stop, take this time to break, and give them time to think about it.