Olia lives with her parents in an old crumbling castle, filled with hidden turrets and secret doorways. When she follows a mysterious cat to one of the castle's roof domes, she finds herself stepping through one such doorway into a magical land filled with wonders. But everything is not quite as it seems: the land is under threat from a scheming magician, Chernmor, and the magic is fading away. With the help of an enchanted band of new friends, can Olia find a way to save both her own home, and the land of forbidden magic?