Bit of an odd scenario. I was out on the road and saw a courier approaching me, but before he got close enough to yank me into his dialog, a troll one shot him. After dispatching the troll, I picked up the note from his dead body, which was addressed to me as an "investor" and asked for assistance clearing out a cave I'd already cleared out an in-game month ago. The note didn't give any objectives and wasn't signed by anyone specific. When I went to the cave and re-cleared it of bandits who had since taken up residence, there was nothing there of note.
Did the troll's untimely appearance glitch out the quest, or is there really nothing more to this note?