I just completed this quest aliance and got my "poison" skill. You go to Stormwind city and talk with Methias Shaw in SI-7. He gives you the "Mathias and the Defias" quest. This is the only quest you need to get the poison skill. 1. travel to westfall past Sentinal Hill traveling east toward duskwood. Just before the bridge turn right and go along the bank until you see Agent Kearmen on your mini map or see Kearman jump down from a tree in stealth mode. Speaking to Agent Kearman completes this part of the quest.