As the changes wrought by the Sundering begin to take hold across the Forgotten Realms, the orcs of Many Arrows decide to take advantage of the chaos and lay siege to the dwarf kingdoms of the Silver Marches, including Mithral Hall. When word of the assaults reach Drizzt and his Companions, Bruenor—the dwarf king who had agreed to a treaty with the orcs more than a century ago—plots revenge.