Between

"...And those individuals deemed prone to dissent and/or impurity shall be detained and/or purged from the Union in the best interest of its citizens."

In the aftermath of the Crisis, Corzibar initiated the Human Atmospheric Adaptation Program in an attempt to better prepare mankind for a newly toxic environment. The Test was created to monitor the HAAP's progress, and to oust Corzibar's less adequate 'Ill-Born' residents. For years the High Ministry has preached of the wonders of the HAAP's success to Corzean citizens, justifying the country's numerous, vast, resource-hungry CO2 Scrubs and the controversial acquisitions of the Ill-Borns who maintain them. Only now, nearly a century later, the High Ministry has begun testing for more than just Ill-Borns. Something new has caught their interest, and now even authorized families are beginning to disappear.

Wren Miller is the only person she knows who can breathe Corzibar's toxic air without a mask. She and her family have faithfully kept her secret from the High Ministry, the rest of Sector 7, and even from her long-time boyfriend Foster. But when she turns 21 and is called forth for the Test, that secret is at risk of being discovered--and the consequences have a much greater reach than even she herself could imagine. Overnight, Wren finds herself trapped in the void between two warring continents, her loyalties split between her family, Foster, and the foreign naval Captain who, together with his crew and the powerful ship Nightjar, may ensnare them all in the single greatest act of sedition their world has ever seen.