This area contains Alliance quest NPCs Kharan Mighthammer and Marshal Windsor, as well as the Horde quest NPC Commander Gor'shak as prisoners. Their cell doors can be opened with lockpicking or its alternatives, or with the Prison Cell Key which can be obtained from High Interrogator Gerstahn, at the center of this area. The key is a white item which is always dropped, and can be picked up by any player with loot rights. It persists beyond the instance, so there is no need to kill Gerstahn for the key on subsequent trips, though she does drop decent loot. Note that the key is placed automatically in your keyring rather than in your bags.