An exciting long and fruitless search

One of the requirements of my unfolding story is that the party have a long and fruitless search for Randall Mourn in the Spiderhaunt Forest.

The challenge is how to make that exciting to play?

The adventure as written says that the party are pretty much looking for someone who cannot be found until the villain of the piece wants to draw the party in.

I am inclined to really draw this out with entire side plots and adventures rather than trying to emulate such a long search and then resolve it in a single weekend of gaming.