Thurindol has traps to trip up enemies within the Towers of the Teeth.
'The orders you intercepted are worrisome, even though I cannot unlock their secrets. We may be sure, nonetheless, that trouble for the messages and messengers of the Enemy does us good.'
Thurindol hands you some Ranger-made traps.
'Take these traps and return to the tower of Carchost. Hide them along the main pathways through the tower. I am sure this will surprise those within. Perhaps they may even start fighting amongst themselves.'
Good places to hide traps can be found within the Towers of the Teeth.
You should hide traps in rubble piles within the Towers of the Teeth.
You should return to Thurindol, who can be found at a small Ranger outpost hidden in the Slag-hills.