In 480 BC, when Xerxes, the son of Darius the Great of Persia, returned to finish the job of conquering the Greeks in which his father had failed, the Athenians consulted the oracle. They were told: "Now your statues are standing and pouring sweat. They shiver with dread. The black blood drips from the highest rooftops. They have seen the necessity of evil. Get out, get out of my sanctum and drown your spirits in woe."