Here Inside the Heart

The girls find their way out of the fast world, but when they think it's all over - the white queen attacks Heatherfield! The girls are having trouble trying to find out how to defeat the queen and her army, while protecting their families and the rest of the people in Heatherfield.
Somehow, they come up with the idea of using their voices to do both - and it is the Song of the Sirens that finally puts the fast world to an end.