Revenge for the Vargul

The questgiver is inside the Underhalls. The entrance to the Underhalls is at 32,32. After you enter go down the first hall and then go left to find Bethod. Then go straight across and down the staircase and you will see the circle of suffering on the side.

For those having trouble with the bug: Start the quest by throwing the sword. Immediately run over to Volgur. Don't let him charge you or Brita and Thane will despawn.

SHADOW VAULT Quest Tree From Whiterock

                    1)It's All Fun and Games{H}
                    1)I Have an Idea, But First...
                    1)Free Your Mind
                    1)If He Cannot Be Turned{H}
                     |->Blackwatch*
                     |
Orgrim's Hammer(H)* 1)The Shadow Vault{H} The Skybreaker(A)*
         |         /  |         \             |
      Opportunity(H)* |         Exploiting an Opening(A)*
                     1)The Duke
                      |      |
2)Eliminate the Competition 2)Honor Challenge---->2)Get the Key
3)The Bone Witch            2)Shadow Vault Decree 2)Let the Baron Know    
 |->3)Reading the Bones      |____________________/
 |  R)Reading the Bones                    |->3)Vandalizing Jotunheim
 |                                         |->D)Leave Our Mark
 |->4)Deep in the Bowels of The Underhalls |->3)Crush Dem Vrykuls!
 |                                         |  D)Vile Like Fire!
 |->4)Revenge for the Vargul               |
 |                                        N)Vaelen Has Returned
4)The Sum is Greater than the Parts       3)Ebon Blade Prisoners
 |                                         |->D)Shoot 'Em Up
3)The Art of Being a Water Terror          |
 |                                        N)To the Rise with all Due Haste!
3)Through the Eye                         6)The Story Thus Far...
 |                                         |->D)From Their Corpses, Rise!
3)Find the Ancient Hero                    |->7)Blood in the Water
 |                                         |  7)You'll Need a Gryphon
3)Not-So-Honorable Combat                  |  D)No Fly Zone
 |                                         |->D)Intelligence Gathering
3)Banshee's Revenge                           +7)The Grand (Admiral's) Plan
 |                                             7)In Strict Confidence
5)Battle at Valhalas                           7)Second Chances
5)Battle at Valhalas: Fallen Heroes            7)The Admiral Revealed
5)Battle at Valhalas: Khit'rix the Dark Master
5)Battle at Valhalas: The Return of Sigrid Iceborn
5)Battle at Valhalas: Carnage!
5)Battle at Valhalas: Thane Deathblow
5)Battle at Valhalas: Final Challenge
Quest zones:
1)Shadow Vault_____2)Savage Ledge_____3)Jotunheim_____4)The Underhalls_____5)Valhalas_____6)Death's Rise_____7)Onslaught Harbor
D)Daily_____N)Not-needed_____R)Repeatable
*Click to see more info about that quest-line.
The Icecrown is done! Leave your comments/sugestions at my comment in Icecrown zone. Thanks everyone who helped me to make it via comments on wowhead and in-game pre-quest tracking.