This is the first of several quests that take place in the Sanctorium of the Trials. This instanced zone is accessed via the doorway beside Szin ( -363, 3, -1271 ) Copy/waypoint -363, 3, -1271.
Pray to the Sanctorium of the Trials torch (examine it) to activate the door. If you have a mercenary they need to be dismissed before praying.