The adventure began when the heroes confronted a powerful warband of raiders threatening the small town of Drellin's Ferry. Under the command of Wyrmlord Koth, the warband of hobgoblins and goblins laired in the ruins of an old keep buried in the dense Witchwood, scouted out the surrounding lands in preparation for an attack. Soon the Wyrmlord and his warband intended to sweep down on Drellin's Ferry and slaughter its inhabitants.
In the course of their fight to drive off the marauders, the heroes learned that Koth's warband was just the tip of the spear, and that a horde of goblins, hobgoblins, and their allies was marching south. They also learned that their enemies were driven on by the fanatical warpriests of not only Izrador but Tiamat as well. Drellin's Ferry couldn't be saved, but the heroes could give the townsfolk time to flee by wrecking a bridge on an old dwarf road the horde needed to cross. There they confronted the youngest of the horde's dragon champions, a green dragon named Ozyrandion.
The war had begun. The heroes divided their time between fighting to stem the advance of the horde and foiling the plans of the other Wyrmlords, whose work would give the horde an irresistible advantage if left to run its course.