Clockwork Secrets — Dru Pagliassotti

The final book in the Clockwork trilogy.

Framed for regicide and trapped on a ship crippled by enemy fire, Taya and Ondinium's diplomatic contingent seem helpless to prevent the well-engineered war their enemies have put into motion. While Alzanan and Demican armies march across Ondinium's borders, Taya and her husband fight airborne battles from the tropical islands of the Cabisi Thassalocracy to the war-ravaged mountains of Alzana. When Taya falls into her enemy's hands, she fears that nobody will be able to save Ondinium from the devastating weapon about to be plunged into its mechanically ticking heart.