Razorfen Downs Quests
Before Entering Instance
Go to the Cathedral in Stormwind and talk to Archbishop Benedictus to start Bring the Light
Outside Entrance to Instance
Talk to Myriam Moonsinger to start A Host of Evil
Inside the Instance
Go to the Murder Pens area of the Razorfen Downs and talk to Belnistrasz to start Scourge of the Downs, which leads to Extinguishing the Idol.