Rebel - The Prometheus Project, #3

At the end of the 21st century, the future of humanity hangs in the balance, caught between the radioactive waste of a half century of nuclear wars and the repressive authority of the Republic. Angels sacrifice their wings to join a secret fraternity of freedom fighters, risking classification as mutants and consignment to the Republic's slave dens. Each warrior is a volunteer, but no angel anticipates the full cost of his fall.
The eyes of the Republic are everywhere. Having sacrificed his wings in a bid to save humanity, fallen angel Armand has a bold plan to assassinate presidential candidate Maximilian Blackstone. When things go awry and his partner is gravely injured, Armand fears he will fail and forever lose the chance to rejoin the angels in heaven. Theodora is a wraith, a woman who officially doesn't exist. She lives in the shadows, taking risks to earn bounties-bounties that buy new life for those she loves.
Captured when her latest hit goes horribly wrong, Theodora finds herself the prisoner of a strong, arrogant stranger. Soon enough, Theodora and Armand find their missions-and their hearts-entwined. But in their desperate attempt to save the world, will they be able to save each other?