Dave and his Undead companions moved through the tall brushes of the Drow Kingdom. Their movements were subtle as they tried to move in with as much discretion as they could.
The Drow were hostile and extremely territorial creatures. From what Dave had gathered they seemed to be comprised out of multiple tribes that had banded together and served the Ash King. They were completely unwilling to let anyone trespass their stronghold.
The giant forest of pillar formations and thick trees was easy to use for hiding and moving stealthily. Unfortunately, if Dave was able to use them to his advantage, it was a given that the Drow, who had lived their entire lives here could do the same. It would be entirely possible that they could have already spotted the conspicuous undead party, while the latter had not seen any of them.