Locked ball and chain
From WoWWiki
The Locked ball and chain is located in Durnholde Keep in Hillsbrad Foothills. Each ball and chain is holding one prisoner: Drull and Tog'thar. [Dull Iron Key] will open one and [Burnished Gold Key] will open the other. A rogue with a lockpicking skill of 100 or higher can pick the locks.
Locations
Objective of
Need to be unlocked for the quest 
[22] The Rescue.
