Barrenlands

When Ehren's sovereign and friend was killed, Ehren, First of the King's Guard, was far away — sent on a wild goose chase by the First Level Ministry, whose number he now believes must contain at least one traitor. When a First Level wizard orders him to stop searching for the assassins and instead to find and neutralize the dead king's distant family, his suspicions deepen to near certainty. And Ehren is determined to find those exiles – if only so that he may guard them with his life. (from the back cover of the Baen Books first edition)