WOW Quest:No Rest For The Wicked (13367)  

Entrance is at 52, 33. The Crystal Altar you summon Alumeth the Ascended from is at the middle back of the vault at 51, 27.

You have 2 minutes to get the four pieces and then combine them or they despawn from your inventory. They are soul bound and must be gathered by one person. Once made, Alumeth's Remains stay in your inventory until he is summoned.

As you enter the vault area, the Heart is in a chest at the front end of the table on your right, the Scepter is in a chest at the other end of that table on your right, and the Robes are in a chest against the back wall to the right of the Altar. The Skull is in a chest against the left middle wall.

You do not have to clear the entire room. Clear enough to get to the four chests first and only then gather them. The Cult Researchers cast Mind Blast that does an aoe knockback and shadow damage, and Wail of Souls that does about 20% mana burn per hit over a several seconds. Alumeth is a level 81 elite with about 260k hp. He melees, casts Mind Flay for about 3k damage per tic over 5 seconds, and Dominate Mind (psychic fear) randomly.