The Shadow Guard — J.D. Vaughn

All is not well in Tequende. The Earth Guild, frequently looked down upon by the Sun and Moon guilds, is beginning to demand fairer treatment by the queen, and whispers of revolution are spreading like wild fire. Brindl Tacora of the Zipa Mines, an earth guilder and now Master of Messages for the Princess, might have to choose sides: join the rebellion, or stay loyal to the crown. But their true enemy remains hidden, and Brindl may be the only one who can help unite the rebels against their foe before it's too late.