Removing the Source

Steps

 * 1) Destroy 3 diseased pebbleberry bushes  (either side of the Butcherblock Canyon)
 * 2) Destroy one more bush
 * 3) Kill 4 Crushbone corruptors (further east in the Grove)
 * 4) Return to Brodo

Rewards

 * One of the following (based on class):
 * Protector's Shortbow (Crusader, Warrior)