Violet Harper is just about to turn seventeen when her world is torn apart. Fleeing from her home and from the creatures who took everything from her, she ends up in New York. The city that never sleeps isn't quite the safe haven that she'd hoped for. It is teeming with demons who are out for her blood.

Encountering three strange allies, Violet soon learns that a war is raging between heaven and hell and that she is directly in the middle of it. The master of hell is planning a hostile takeover of Earth. It is apparently her destiny to stop him from breaking open the gates to the underworld and releasing a flood of ravenous demons.

Armed with only her wit and sarcasm, it will take strength and courage that she never knew she possessed to face the ordeals ahead. What Violet doesn't know yet is that she won't be alone. The guardian angel she'd always thought was just her imagination is very real. He will be watching over her and guarding her back as she faces the minions of hell.