Adeline is a a exorcist in a apocalyptic world pureg by angels.

1955 angels just show up all over earth and declare that humanity is beyond saving or redemption and that they need to die so the next human race can prosper. So Angels rain down on humanity and slaughter them.

Adelines older brother Isaac managed to save her when she was only 2 years old and has ever since raised her and tried to give her a normal life. Even with how the world is right now.

Adeline loves her big brother dearly