The Missionary

Background
As you head out of Ostergar to find blood vials for your Joining Ritual, after a minor encounter with some wolves you will stumble upon a dead body in the water. If you pick up "A letter" from the body you will be given the following quest:

"You found a corpse near the entrance to the Korcari Wilds.A letter on the corpse detailed a path thourgh the Wilds that should lead to the place where the deceased is meant to meet his father.Consult the note "A letter to Jogby" for more information."

Walkthrough
As you look at the body move left until you reach some corpses that are hanged by a fallen tree.Go straight ahead ( you should see a flooded tower on your right now) until you see an archway in the water.Go near it and you should be able to see a path made out of roots on its right now.Follow the path fight the wolves, open the chest and you're done.

Result
Upon completing this quest your reward is the loot from the chest : one 2 handed sword and some arrows.