TWO HUNDRED YEARS AFTER THE FORBIDDING WAS BROKEN, Santhenar is locked in war with the lyrinx - huge, intelligent, winged predators from the void who will do anything to gain their own world. And despite the development of battle clankers, and mastery of the Secret Art that powers them, humanity is losing …

Tiaan, a lonely crystal worker in a clanker manufactory, is experimenting with an entirely new kind of crystal when she begins to have extraordinary visions. The crystal has woken her latent talent for geomancy, the most powerful of all the Secret Arts, and the most perilous. Geomancy is likely to kill her before she masters it. It is a talent that allies and enemies alike are desperate to control.

Falsely accused of sabotage by her rival, Irisis, Tiaan flees for her life. She is also hunted by the 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 on all the Three Worlds, where a nightmare awaits her …