Five elements. Four friends. One city and its sinister shadow. This epic new middle grade series is filled with awesome elemental powers, nightmarish creatures, and nonstop adventure. When Gabe Conway and his friends find a strange old map in his uncle's office and follow it to a crumbling secret chamber beneath San Francisco, they think they re just having one last adventure before Gabe moves away.

Don't miss the epic, action-packed finale of the middle grade series School Library Journal called "extremely entertaining and sure to be popular with fans of Rick Riordan's Percy Jackson books and the 39 Clues series." Five elements. One terrifying new world. One final stand. Gabe and his friends thought they had finally discovered a way to destroy the shadow dimension of Arcadia forever. But they were tricked-and instead of saving San Francisco,...