When Tachi and Caitlin fall through a West Virginia cave 'portal' and into a hive of stingers on the world of Tessene, they think they are in big trouble, but that's only because they have not yet met Sorcet, a deru of the Gray Guild who needs two more taidar to protect — and die for — her.Sorcet conducts dangerous missions for the Gray Guild library and is determined to close the portals to stop anything or anyone else from arriving in Tessene to disrupt that world.Sorcet, Caitlin and Tachi avoid several assassins and return to the stinger hive, fight their way through a swarm of giant insects, and close the Firestone Portal. How they get there, and the stunning ending, are the focus of The Firestone.