All along the Five Rivers the River Folk thrived. Their trade networks flowed up and down every stream through every village, town, and city in the land from the Eastern Icepeak Mountains to the Western Mountains of Mist, from the Frozen South to the tropical delta marshes of the Mother River.

Then came the red-spot fever. Everywhere the traders went the fever followed. It killed. First the elders, then the babes. Those with the most knowledge of how to heal were among the first to die as they tried to tend the sick. Mothers and fathers died tending their sick children.

Some of the young never got sick. Some got sick and recovered. Those who fled the cities sometimes avoided the sickness until another refugee encountered them, and then all bets were off.

In a few short years the cities were empty save for the insane cult of people so maddened by grief that they turned to animating the corpses of their loved ones. But in a few more years all but the most powerful of these were gone.

Thus, when the Krydens came across the sea they found wandering tribes wary of each other and even more wary of the overgrown cities along the rivers. Their simple, even childlike cultures and languages, gave the invaders the impression they were in need of paternal guidance.