This is the 4th of the Books of Bayern and chronicles the adventures of Rinna, little sister to Razzo.
Rinna stuggles with her inner demons and leaves her beloved forest and winds up going with Isi, Enna and Dasha, who she calls the "fire sisters" on a mission to save the kingdom. Rinna discovers that she has her own types of "speakings" and she plays the key role in saving the kingdom.
Another wonderful book in this series. I hope that there will be more.