Aleja whiles away her days in her family's dusty tavern in Seville, dreaming of distant lands and believing in the kind of magic that she's only ever read about in books. After all, she's always being told that girls can't be explorers.

But her life is changed forever when adventure comes for her in the form of a fabled vessel called the Ship of Shadows. Crewed by a band of ruthless women, with cabin walls dripping with secrets, the ship has sailed right out of a legend. And it wants Aleja.

Once on board its shadowy deck, she begins to realize that the sea holds more secrets than she ever could have imagined. The crew are desperately seeking something, and their path will take them through treacherous waters and force them to confront nightmare creatures and pitch-dark magic. It will take all of Aleja's strength and courage to gain the trust of her fellow pirates - and discover what they are risking everything to find.