Speak with Vimminy Crix ( -212, -56, 39 ) Copy/waypoint -212, -56, 39 who tells you to locate the Overlord.
Head to Overlord's Plaza and then enter the portal to the Citadel ( 10, -20, 10 ) Copy/waypoint 10, -20, 10 in the center of The City of Freeport to speak with Overlord D'Lere. You need to be ungrouped to enter the portal.