Kate Harker is trying very hard to be like her powerful and ruthless father. She is finally coming home to prove it. August Flynn just wants peace and to be human. He is a monster who can steal a soul with music. Monsters are created by violence and sin. Kate and August live in their divided city. Harker controls the monsters and people with violence and money.. The other side of the city is controlled by the Flynn family who uses three powerful monsters to keep sin under control. Their truce is in danger of being broken and the monsters are rebelling. Kate and August might just have a way to keep the peace. This is a difficult task when it is hard to tell the good guys from the bad. Who are the real monsters?