North of Dingtao county in Caozhou there is a marsh, and those who lived nearby mostly gathered mussels, fish, and turtles to sell for a living. In the second year of the Zhenglong era of Emperor Hailing of Jin, in mid-spring, a Jurchen named Asar was the county magistrate.
He dreamed of a guest in a green robe, black cap, black boots, and a leather belt, who came in holding a tablet and said: “My kind has lived under your administration for generations, and our descendants have all received your merciful protection. But unhappily we are caught and killed by the common people for food, and then resold to others, and soon none of my line will survive. May the worthy magistrate take pity and forbid it a little; the grace would flow without end, and we shall think how to repay.”
Asar promised in the dream but had no time to ask what creature it was or where it lived. Awaking, he pondered deeply but could not fathom it. The next night he dreamed again; he asked his clerks and soldiers and consulted a practitioner of the arts, but none could say what it meant.
By late spring the weather was clear and warm, and the lakeside folk went in groups of tens and hundreds, stripping off and entering the water with nets and baskets, catching many times their usual haul. Suddenly mist shrouded the sky, the waves rose like mountains, thunder shook the air, and a huge creature six or seven zhang long, shaped like a flood-dragon, sprayed clouds and smoke, wrecked the banks, and breathed a bitter cold. All threw down their catches and raced for dry land; of them, a tenth or more were seized by the great creature and nearly half drowned.
Only then did the crowd understand the magistrate’s dream. From then on none dared fish there again.