Tetrarch

SANTHENAR IS ON ITS KNEES. The war with the alien lyrinx drags on, and humanity is losing it, but there is worse to come.
The Aachim have invaded with an irresistible force - a fleet of battle constructs. Cursing humanity for the loss of Aachan and his own clan, the embittered Aachim leader, Vithis, demands half the world in reparation. The council is in no position to resist. But even if they agree to his demands, can anything satisfy his thirst for vengeance?
Tiaan is in despair. Her life lies in ruins, and now she is being hunted through the abandoned city of Tirthrax by an implacable Nish, who blames her for the attack.
The future of the world rests in the hands of three flawed people: Tiaan, whose geomancy holds the key to the power that can save or destroy them; Nish, who has sworn to bring her to justice; and Irisis, whose great talents are hidden even from herself.