When then hill tribes came down conquering the city states of the coastal plain, nothing could stop them. In desperation, the King of Kings, Ur-melem-nungal, had the heads of the great priests that died in those battles, saved. His alchemists placed them in lead boxes mounted on poles. And the boxes had a hinged front with a thin brass chain attached. And they were carried in front of the army like standards. And when the enemy was met they pulled the chains and opened the boxes. And the hollow mouths of the heads continued their last prayers. But they came out as a high keening and would stop for nothing. It is said, a whole army dropped its weapons and fell asleep at the dark prayer of one, that another caused a wind of fire, and a third had to be buried for it wouldn't stop raining for as long as it screamed.