One night, under the cover of darkness, three sleeping children were wrapped in blankets and taken away from home to escape a deadly danger. Since then, Kate, Michael, and Emma have changed many orphanages—without stopping their hope that one day their parents will come back for them. But one day, the children end up in a place even more strange.
They become the only residents in a huge, half-abandoned house and find a mysterious office filled with old books. When the children touch a strange book with a green cover, they are transported into the past—where they must fight a witch, learn who their parents were, and try to change the future in order to save the residents of a small town at the foot of a waterfall and return home.