Deep beneath the Harbinstone Mountains, the dwarves of Hammerdeep uncover a wonder beyond imagining: a forgotten volcanic shaft whose black walls glitter with countless diamonds.
A quiet metalsmith named Boic, more devoted to shaping iron than seeking glory, must find the courage to become something more than a master of metal. He must become a defender and leader of his people against an enemy older and more terrible than any they have ever before faced.