Tetrarch: The Well of Echoes, Volume Two (A Three Worlds Novel)

Santhenar is on its knees. War with the forces from beyond the Void shows no sign of ending. And there is worse to come. The Aachim have invaded with a fleet of formidable battle constructs and the price for their withdrawal is half the globe. The future of the world now rests in the hands of just three flawed individuals: Tiaan, whose knowledge holds the key to a power that can yet destroy all foes; Nish who has sworn to bring the renegade geomancer to justice; and Irisis, whose great talents are hidden even from herself. Now Tiaan is leading her people in a last desperate stand against the Lyrinx... but if they are to survive she must master her new powers or be destroyed...