How to unlock: Talk to Kern in Gref's Rest (M1,7).
While at Gref's Rest (M1,7), you will notice a man holding a loud conversation near one of the walls; that's Kern. After you talk to him, you will learn that he is haunted by a problem. He hired a paladin recently to kill one of the families living in the neighborhood. In the mean time, he came to regret this decision and is now looking for someone who could stop the assassination.
First, head for Whitestone Hollow and locate Haddi's House (M6,2) in its south-eastern part. Unfortunately, once inside you will discover that the family has already been murdered. Approach the body and "touch" the spirit of the dead person. While you are here, you can also loot the house. One of the stashes is located under the pillow.
Haddi's spirit will tell you that the trio of killers is still looking for his son - Eska. He should be in the mill in Stagmire Village. To find him, you have to leave White March and go to Stagmire. Once you're there, enter the mill located in the western part of the village.
Upon entering the mill, you will see a cutscene showing Eska being attacked by a group of paladins led by Cevestin.
If you kill the paladins and save Eska, you will receive 2000 coins from him and your reputation in Stalwart Village will increase. You will also receive additional 3000 coins from Kern (M1,7).
You can also try to diffuse the situation. To do this, you are going to need 18 points of Resolve and many attempts, because it won't be not easy to lead the conversation in the right direction. Finally, you will get to decide whether to leave Eska alive. If you do, you will receive 3000 coins from Kern.
If you decide to kill Eska, you will still have to talk to Kern. You can simply ignore his threats, receiving only the experience points. You can also attack him, but keep in mind that in that case you will have to defeat everyone in the inn. If, however, you have 16 points of Resolve you will receive 5000 coins from him.