Queen Thalestris Cynane rules the empire of Nocturnia with an iron will, a brilliant mind, and an appetite for power and passion that defies every convention of her court. When her exiled half-brother, Tiberius Orestes, returns with a mercenary army determined to reclaim the Obsidian Throne, Thalestris discovers that the greatest danger may not be waiting beyond her borders—it may already be hiding within her own court.

Surrounded by Lady Xanthe Cyrene, her trusted confidante and lover, and Lord Commander Dardanos Severus, her fiercely devoted warrior and lover, the Queen must navigate a dangerous web of betrayal, forbidden desire, political conspiracies, assassins, and impending war.

As Tiberius prepares an invasion, Thalestris launches a daring campaign to uncover the financiers behind the rebellion and destroy the enemy's supply lines before the first armies reach her kingdom. But every victory brings her closer to a darker truth: someone powerful is determined to see her crown—and perhaps her life—destroyed.

With kingdoms on the brink of war and desire becoming another weapon of power, Thalestris must decide how far she is willing to go to protect her throne, her empire, and the people she loves.