The young Prue Shackleton travels from London to Cornwall to visit her beloved aunt Phoebe, who has just become a widow. On the train she meets Charlotte, a sad little girl who comes from a broken home.

11-year-old Nina and her mother Birgit move to the countryside. But while Birgit seems to cope very well with the upheaval, the shy young girl only feels accepted when she joins a girl guide group. Nina's new teacher for Religious Education, the organizer of the group, and the parson belong to the fanatically pious "Legion Of The Holy Angels", a sect preparing its members for the final battle between demons and angels. As Birgi's behaviour doesn't conform to her daughter's ideas, Nina sacrifices a black kitten which allegedly has a bad influence on Birgit. But this only makes things worse, for Birgit eventually forbids her daughter to go to the scouts' sessions and thereby loses her trust. Nina's friend Miriam is having a hard time being accepted by the scouts and leaves them when she isn't allowed to participate in an important ceremony. Nina is faced with a difficult decision...