Mists of Everness by John C. Wright
Young Galen Waylock is the last watchman of the dream gate beyond which the ancient evils wait, hungry for the human world. For a thousand years, Galen's family stood guard, scorned by a world that dismissed the danger as myth. Now, the minions of Darkness have stirred in the deep and the long watch is over. An army of mythic monsters has invaded our world, and Galen and his friends have begun to fight them. This volume continues a towering fantasy that will inspire readers everywhere.