The Jewel of the Kalderash (The Kronos Chronicles Series #3)

Upon arriving in the Romany homeland to deliver the Mercator Globes, Petra Kronos, Tomik, and Neel formulate a plan to save Petra's father, who has been transformed into a Gray Man. But when a long-held secret is revealed, Neel finds himself bound to his country. The friends are quickly swept up in an epic battle for power. Thrones are at stake. Spies are afoot. Murder is common. Worst of all, Prince Rodolfo is close to becoming emperor, and ruling half of Europe.

How much is Petra willing ...