Time: 11:15 PM EST
Frequency: Unknown (Twice in a row)
World name: Lamia
Character name: Tama Softpaws
NPC name:Willielmus
Monster name: None
Class/Level: Dragoon/50
Party or solo: Party
In-game time: approx 7PM
Area and coordinates: Coerthas Central Highlands/The Aurum Vale V15-H35
Steps:
1.Collect quest Gilding the Bilious(Immortal Flames)
2.Speak with Willielmus outside The Aurum Vale
3.Enter The Aurum Vale using the Duty Finder
4.After completing the dungeon, the quest reverts back to step 2.
5.If you speak with the npc again, he gives the quest to enter Aurum Vale again.
Abandoning and re-completing had the same results.

Entered the duty finder with 3/4 in party before hand.