Grand Theft Artifact

In the middle room where your groups corpses are click on the base that does not have a ghost above it dead center of the room the R'Jhere's Severed Hand will spawn Mayong Mistmoore. Use the Illusion of the Head Archivist (can not be in combat) and then speak to him. Once you have finished his text you can open the chest at -87, 17, -364