Having a guardian angel wasn't exactly a concept that was unheard of, though it was rare and reserved as a task of repentance for angels who have done something mildly bad. But Harry Styles, a justice driven policeman, finds himself saddled with a guardian demon who is no less annoyed by this arrangement than he was. Maia Ryder had been living happily as one of the biggest gang leaders in New York City, using her status as a demon to exert cruel punishment on people who escaped punishment or didn't get the punishment she felt they deserved. Finding herself bound to a mortal policeman who seemed to go looking for trouble was not her ideal situation but rules were rules and she was forced to protect him. Then, something unheard of happens, especially for a demon. She grows fond of him, despite any romantic relationships between a demon or angel with a human being strictly forbidden. Will she be able let him go or will she do something no demon has ever done: fall in love and willing give him her heart?