Being a Captain of some standing, I decided to see if I could go to Andrath to beat Sharkey's captain by myself. Sharkey's men are a very organized group of brigands backed by Saruman, allegedly. I had failed the quest before, and this was mainly because there is one choke point where you will aggro 5 level 13-14 brigand enemies. And even at level 21, with a herald, they wear you down pretty quickly. Luckily I made it through by sheer luck.
I went back to talk to Saeradan, the Ranger stationed in Bree-land, and he told me that Sharkey's men and a group of White Hand orcs were going to ally and possibly overrun Breeland! I had to go to the cave to stop it.