You found a letter with Ulgorn's name on it while hunting near the lake. You should take it to the boss.
Step 1. Take the letter to 'UlgornThe Ulgorn Raider Boss. He stands at the center of Aldelle Village in Ishalgen. Although tough and ignorant, he doesn't hold grudges..
Step 2. Take the letter to LinevirA Soul Healer of Aldelle Village in Ishalgen..