The Conqueror Worm is An OSRIC(tm) module designed for 6-8 adventurers of levels 10-14.
Over five centuries ago, there came unto the arctic lands of the North from a far removed dimension an elder being of unfathomable menace. The White Worm, as it was called by the scholars, was a colossal creature with rubbery, corpse-white skin. The primitive humans the foul beast encountered were ill-equipped to deal with the manifold, eldritch magicks in its possession. However, before the dread worm could wholly enslave the Northern lands, the great frost giant jarl Harold Hardrada managed to deal it a near-fatal blow. And so, the White Worm entered into a deep recuperative sleep until such time as it felt strong enough to challenve the kingdoms of the North once again.
Unfortunately, the White Worm has just awakened from its centuries-long slumber, and it trying to build up its magical army once again. The PCs can pervent the completion of such by retrieving the magical weapon of the long-dead frost giant jarl and then putting the abominable White Worm to the sword in its ice-walled citadel.