Serafina is a girl of the night, she is CRC (Chief Rat Catcher) of the Biltmore Estate. But one night she sees I a different kind of rat, one that steals little children, and wears a black cloak. It goes after Serafina but she is to clever to get caught. But as the adults of the estate are searching for the lost (stolen) children, Serafina breaks her fathers biggest rule by making herself seen and talking to one of the people from upstairs, and if that isn't bad enough it happens to the nephew of the house owner, Braeden Biltmore. Serafina tells Braeden about what she saw and they become quick friends and cohorts in the rush to solve who is behind the black cloak and how to stop him. Especially, since it seems that Black Cloak is out to get Braeden. Can Serafina stop Black Cloak before it gets her only friend, and is it still possible to rescue the other children?