The Waiting Game

Overview
Summary
 * 1) Speak with the Voice of Grenth in the Temple of the Ages, Zin Ku Corridor or Chantry of Secrets should you wish to volunteer your services in the fight against Dhuum.
 * 2) The Voice of Grenth suggests you prepare for the battle against Dhuum and will notify you should the situation change.
 * 3) Speak with the Reaper of the Labyrinth to get an update on Dhuum's state of imprisonment.
 * 4) Completing all quests in the Underworld will release Dhuum.

Obtained from
 * Mad King's Steward in Lion's Arch or Kamadan, Jewel of Istan

Requirements
 * Access to Prophecies or Nightfall.

Reward
 * 15,000 XP
 * 5,000
 * 100 Trick-or-Treat Bags
 * 1 Passage Scroll to the Underworld

Dialogue
 * "There is nothing more I can do. Once Mad King Thorn has appeared in this world each Autumn, his power over the mortal realm begins to fade and he must return to his Mad Realm. As the Mad King's steward, I must return with my lord to make him pie and groom his invisible pony. Now all of Tyria must face the return of Dhuum. If you wish to hold back the coming night, seek out the Voice of Grenth and offer your assistance."


 * Accept: "It will be done. I shall speak with the Voice of Grenth."
 * Reject: "I've had my fill of the Underworld, thank you."

Intermediate Dialogue 1 (Voice of Grenth)
 * - before the battle begins
 * "The Voice of Grenth hears and appreciates your offer of assistance, mortal. Stand ready; we may have need of your skills in the coming battle. We will summon you when the time comes."
 * - after the battle begins

Intermediate Dialogue 2 (Reaper of the Labyrinth)
 * "Once again we meet, mortal. These are dark times. The minions of Dhuum rampage unchecked, and their ranks swell with every passing day. If they are not defeated, Dhuum's servants will overwhelm the Underworld. Herein lies the dilemma: the minions must be stopped, but each small victory over Dhuum's forces hastens the Ender of All's arrival. We Reapers need your help to battle the legions of Dhuum, but know that if you do our bidding and complete all the tasks laid before you, Dhuum will surely break free into the Underworld. It is a heavy responsibility we have laid upon your capable shoulders."

Reward Dialogue

Followup

Walkthrough
Enter the Underworld as normal and complete all the quests the Reapers give you. When they are complete, walk towards the Hall of Judgement and accept the quest reward from King Frozenwind before entering the now open door of the Hall of Judgement. Upon entering, the party will encounter Dhuum. He will initially be an NPC, but then will let out a shout about his return and become hostile. At that point, the doors to the Hall will close and the party forced to fight him. At the same time, every Reaper of Grenth will appear in a large radius next to the walls of the Hall and continuously cast Dhuum's Rest.