Two hundred years after the Forbidding was broken, Santhenar is locked in war with the lyrinx ? intelligent, winged predators from the void who will do anything to gain their own world. Despite the development of battle clankers and mastery of the crystals that power them, humanity is losing. The enemy is destroying their nodes of power, one by one.

Tiaan, a lonely crystal worker, is experimenting with a new type of crystal when she begins to have extraordinary visions. The crystal has woken her talent for geomancy, the most powerful of the Secret Arts, and the most perilous. Geomancy is a magic that humanity’s allies and enemies alike are desperate to control, but it is deadly to the user.

Falsely accused of sabotage by her rival, Irisis, Tiaan flees for her life. She is hunted by the alien lyrinx, Ryll, who plans to use her in his dreadful flesh-forming experiments. Only geomancy can save her. Struggling to control her talent, Tiaan follows her visions all the way to Tirthrax, greatest peak in the Three Worlds, where a nightmare awaits her…