Kingdom of the Cleansed Quest
In this quest you’ll meet Tristian. Finally, he will come to your throne room and inform you about a few cult member who has come to town. Go to the city square, find Tristian’s icon on the map and head for it.
Talk with the girl standing next to him then with Tristian. After that, open the world map. Move to the right and down, away from the capital and also towards a new location — Secret Sanctum (it’s beneath the bridge).
After arriving at the place of ritual and investigating it, start a battle with the worshipers and a man in a hood.
First you ought to kill him and his helper, and all the others will run away. A mysterious guy will threaten you with a Goddess and disappear.
Now you simply need to go back to the town square, locate Tristian and speak with him. This may end the pursuit, and you’re going to get 900 XP.