Seems to be broken in 6.0.2. I was unable to loot anything but the blue item from the cache. Perhaps it has something to do with how quest items are no longer in the inventory?
Quest
Lost Treasure
A World of Warcraft quest in The Mechanar. Facts and objectives from the current retail game data.
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Found just to the left of the elevator that goes up to the second floor after you kill Gatewatcher Gyro-Kill and Gatewatcher Iron-Hand. See the screenshot for more detail.
The item becomes unlocked after killing [npc=19218] and [npc=19710]. There's no need to do anything more. The elevator won't unlock until you've killed the two Gatewatchers anyway.
Quest facts
The client quest POI data records no map location for this quest, so no map is shown.
Check whether you have already completed this quest
in-game: /run print(C_QuestLog.IsQuestFlaggedCompleted(29659))
Description
I sense that one of my kind's artifacts has been taken and stashed away in the Cache of the Legion. We cannot give them time to discover its power. If you would kill the Gatewatchers and retrieve it for me, I would be most grateful.
Getting there
Inside the dungeon: The Mechanar
The mighty Tempest Keep was created by the enigmatic naaru: sentient beings of pure energy and the sworn enemies of the Burning Legion.
Bosses in the Adventure Guide, in order: Mechano-Lord Capacitus, Nethermancer Sepethrea, Pathaleon the Calculator.
Entrance: Tempest Keep, Netherstorm at 70.6, 69.8.
Instance text, bosses and entrances are the client’s Adventure Guide data.
Community notes from Wowhead · 26 comments
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