The Long Hunt
You receive this quest after you invite Sagani into your party (M16,1). It consists in reaching the location seen in the vision that your character had during the first meeting with the dwarf.
To find the first location from Sagani's vision, you need to go to the Perlwood Bluff and approach the cliff (M27,2). You do not find Persoq there, but you will have a vision, in which you see the adra arch.
Go now to the Elmshore. Find the adra arch (M35,3) there, touch the sphere of energy, and you will have another vision. This time round, you need to find a forest with ruins.
Your next destination should be Northweald. Approaching the cave (M57,4) initiates a conversation with a group of hunters, who hunted the great white stag. It is at the brink of dying. Sagani will be disappointed with what she saw, and with Persoq, but she determines that her job is done.