@jskellogg I’ve been toying with something similar for my homebrew game. I had thought something along the lines of an ancient guardian. Not necessarily evil, but it views the accidental intrusion into its ‘domain’ as an act of aggression and deals with it in a heavy-handed manner. Problem is I’ve still got to work out how this response arrives. Does it disturb a tribe of goblins which flee in terror right into the new settlement? Or something else that leads the PCs back to it eventually.