In Heart of Nightfang Spire, the player characters are drawn to investigate Nightfang Spire, a lonely stone tower in a barren land. The vampire lord Gulthias, servant of the great dragon Ashardalon, has returned to the tower which was once the main cult temple of Ashardalon. The vampire prepares for the dragon's return by awakening the other cultists who had preserved themselves as undead creatures.