Teenage cousins are accidentally transported to a world of magic and peril in this YA steampunk fantasy from two New York Times–bestselling authors.

Born only five hours part, cousins Gwen and Vic have always been close. But when Vic's mother disappeared, and Gwen's parents died under mysterious circumstances, they needed each other more than ever. Now both fourteen years old, they're about to face yet another challenge together—when Vic's scientist father accidentally transports them through a magical doorway to the island of Elantya—a wonder-filled place of magic and steampunk technology.

Vic and Gwen are soon caught in a tempest of ancient magic, bizarre gadgets, vicious creatures. But before they can return home, they must face fierce battles in a territorial feud with the sea-dwelling merlons, an age-old conflict between the bright and dark sages . . . and Gwen and Vic's own mysterious roots.

"A charming young adult novel . . . promises to keep readers turning the pages for many books to come." —Terry Brooks, The New York Times–bestselling author of The Sword of Shannara