Sharra's world is a terrifying place. Violent seismic 'Shifts' and outbreaks of an all-consuming black fire radically alter landscapes on an increasingly frequent basis. Only the Map Makers can predict where the Shift will fall, and Sharra, daughter to one of the most famous Map Makers, yearns to join their ranks and break a cultural taboo which forbids female cartographers.

Sharra's father, Lord Milton, is one of the few to challenge the current order, but his shadowy past limits his political reach and his second wife, Lady Ivory, is determined to manipulate him to ensure a privileged future for herself and her daughter, Jayne. The main obstacle standing in Ivory's way is Sharra.