The glyphs illustrate an emissary of the Qiraji meeting with three silithid at the bones of a large dragon. Above the glyphs is what I can only assume to be a code of some sort. This code might very well be the key to summoning the emissary.$B$BI will create a copy of the glyph code that you must use in the sand at the Bones of Grakkarond. If I am right, the Overlords will come thinking that new data is ready for transmission. Strike them down and confront the emissary. He holds the key to the crystals...