When Kate meets Nathan, he reveals the existence of the Guardians—men and women with God-given "superpowers.ˮ But not all Guardians honor their calling to protect innocent lives. Some choose to prey on the innocent instead.

Nathan's touch leaves Kate with a flame-shaped mark on her wrist, the sign she's been chosen as a Guardian. Suddenly she finds herself in the middle of a conflict that's been burning between the Guardians and their Fallen brethren for over a thousand years.

While Kate waits for her dormant ability to emerge, she has to endure combat training with Hassan, an ex-terrorist who enjoys taking shots at her already low self-esteem. He also draws out the side of her that wants to fight back, and if Kate can find the courage to believe God is offering the life she's always wanted, Hassan might just be the one to help her start living it.