The Shadow Isle Av Katharine Kerr

Book fourteen of the celebrated Deverry series, an epic fantasy rooted in Celtic mythology that intricately interweaves human and elven history over several hundred years. As the tale of Deverry and her people draws near to its close, questions will be answered and mysteries uncovered... The wild Northlands hold many secrets, among them the mysterious dweomer island of Haen Marn, the mountain settlements of Dwarvholt, and the fortified city of Cerr Cawnen, built long ago by escaping bondmen from Deverry itself. And just who or what are the mysterious Dwgi folk? Thanks to the Horsekin, who continue to push their religious crusade south toward the borders of the kingdom, the human beings of Deverry and their elven allies realize that the fate of the Northlands lies tangled with their own. Although the dwarven race holds strong, the island of Haen Marn has fled and Cerr Cawnen seems doomed. Only the magic of Dallandra and Valandario and the might of the powerful dragons, Arzosah and Rori, can reveal the secrets and save the Northlands from conquest.