Accept any help the Theramore investigator offers, even feed him a tidbit or two of information if you'd like, but save your real findings for me.
When completing this quest, Tarem gives you the buff "Spread Reflective Dust", which lasts for 2 minutes. While buffed, 3 arrows appear in the general area. Hoofprints are next to Tarem, a Theramore Guard Badge is on the floor of the Inn, and a Black Shield is over the fireplace. Inspect each of the items to pick up a new quest. Players can ask Tarem to reapply the buff if necessary.
This is part of The Shady Rest Inn quest chain.