"There is a Ninja in the Cave of Earlsome. We don't know what he is doing but whatever it is, we don't like it when people sniff around."
How to Complete
The "ninja" is a girl named Chiyo, hiding on the 7th floor of the Cave of Earlsome. Go there and defeat her.
Chiyo has only a level 45 Tengu, but enhanced to over 13k hitpoints.