Grimm Fairy Tales: The Dream Eater Saga #1

As a little girl, Baba Yaga's mother uses stories of the Dream Eater to get her to go to bed. Later when the Dark One breaks into their home to take the Book of the Lost, her mother tries to reassure her - saying good will always triumph over evil. But the Dark One kills her mother and Thane arrives too late to help. Baba Yaga decides that her mother was wrong - good does not always triumph over evil. This sets her on a lifetime course of vengeance.