Beyond the Martial Empire and within it, the threat of war looms ever larger. Helene Aquilla, the Blood Shrike, is desperate to protect her sister's life and the lives of everyone in the Empire. But she knows that danger lurks on all sides: Emperor Marcus, haunted by his past, grows increasingly unstable and violent, while Keris Veturia, the ruthless Commandant, capitalizes on the Emperor's volatility to grow her own power--regardless of the carnage...

"Elias, Helene, and Tavi are Fivers - in training to become elite military recruits for the Martial Empire at Blackcliff Academy. When they're sent on a dangerous mission to steal a heavily-guarded poison on Isle South, the soon find themselves up against surprising enemies - including other recruits. As the true horror of their assignment is revealed, these three will begin to confront the harrowing realities of Martial rule, their place in the system...