Can't Turn in Quest - Taretha's Diversion

Taretha's Diversion is offered by Keepers of Time NPC, Erozion, at the entrance to the Old Hillsbrad Foothills Caverns of Time dungeon. After the quest requirements are completed, it must be turned in to Thrall in the Keep basement before anyone uses the dialogue option to continue with the dungeon storyline. If a member of the party chooses the dialogue option before anyone in the party turns in the quest, that player will not be able to turn in the quest unless they come back to the dungeon and complete it again.

This is not a bug. Because of how the storyline works, if you aren't able to turn in the quest to Thrall before the dialogue is started, you would not be able to start and complete the follow up quest. It is very important that party members confirm that everyone has turned in Teretha's Diversion and picked up Escape from Durnholde if they are on this questline before using the dialogue.

Customer Support is not able to assist if you were not able to turn in your quest because another party member used the dialogue option. You will need to complete the dungeon again to turn in the quest.