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?

Dive beneath the waves with this spell-binding adventure of friendship, forgiveness and bravery, set on the shores of Papua New Guinea, perfect for fans of Katherine Rundell and Eva Ibbotson.

"I want to be able to call the sharks. Teach me the magic and show me the ways."

Blue Wing is desperate to become a shark caller, but instead she must befriend infuriating newcomer Maple, who arrives unexpectedly on Blue Wing's island.

At first, the girls are too angry to share their secrets and become friends. But when the tide breathes the promise of treasure, they must journey together to the bottom of the ocean to brave the deadliest shark of them all...