Now sixteen years old, Tilly is determined to go home, even though she doesn’t know where home is or how to get there. All she has is the map that her mother made her swear to protect with her life.
Tilly soon finds herself plunged into the world where it all began—a world of oceans, sailing ships, and feuds between ancient magical families. She joins a fleet in search of the secret that her map holds, the secret that has been guarded by her family for thousands of years.
As Tilly learns how to cast sprites and make potions, she and her three friends must follow the trail of murky clues left by her ancestors before time runs out. But the closer they get to their destination, the more Tilly learns about her true identity–and everything is not as it seems.