Dark Keeper Key

The Dark Keeper Key drops from one of six possible Dark Keepers which spawn after a party member looks at the portrait in the Black Vault anteroom. This key is needed to open the Dark Coffer in the Black Vault. Each Keeper spawns in a different location, which the portrait gives clues to.

Source
This item drops from:
 * Dark Keeper Bethek in the Black Vault
 * Dark Keeper Pelver in the Domicile
 * Dark Keeper Zimrel on a bench above the arena
 * Dark Keeper Uggel in the Hall of Crafting
 * Dark Keeper Ofgut in the West Garrison (at General Angerforge's location)
 * Dark Keeper Vorfalk in the Grim Guzzler