In the Land of Aeon: The Ring of Eman Vath by Hal Emerson
The land of Aeon has been at peace for a hundred years, and towns and cities like Dunlow prosper; there is a new, just king in the city of Caelron; and the Sorev Ael of Var Athel keep the dangers of the Wilds at bay. But when an ancient artifact is found and brought through Dunlow, a fleet of ships with black sails invades in the dead of night, leaving hundreds dead and hundreds more captured and enslaved. The land of Aeon is left reeling, and the lives of three young people are changed forever.
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Hal Emerson lives in San Francisco, where he writes and works in high tech. His favorite book is East of Eden, and he has an undying love of raspberries and dark chocolate.