As a Shield, William Grayson's entire life centered around combat training for the sole purpose of protecting the Circle. To him there was nothing else in life, no other temptations, no goals, no dreams of family. He and the other Shields were trained warriors; a tolerated, necessary evil in a world where the only religion was peace. Aside from them, hundreds of years had passed since humans had engaged in any type of war, aggression, or even self-defense. The Last War had consumed the entire planet, destroying nearly everyone and everything. The fleeting remains of humanity had managed to rebuild the Twelve Cities focused entirely on establishing a peaceful people and a peaceful planet.

When the aliens came, they had no intention on participating in this utopia humans had spent centuries perfecting.

Grayson and the few remaining Shields must train and lead the very society that before had considered them a nuisance. Forced to reconcile new emotions he was forever immune to, and to engage those who hated what he stood for, Grayson must learn to go beyond his training as he slowly realizes that he is now responsible for not only the liberation of his planet, but to bring a new definition of life to every last human.