As the five Kingdom Keepers enter high school, everything is about to change. The Maintenance Base, which controls all four parks in Disney World, is under attack by the Overtakers, a group of determined to change Disney forever. Relationships among the Keepers are no longer as simple as they once were. In fact, nothing is as simple as it once was.

The Kingdom keepers and their friends discover that Maleficent and the Overtakers are plotting a catastrophic event that could have repercussions far beyond the world of Disney unless they solve a puzzle that is revealed during the Disney Cruise Line's inaugural passage through the Panama Canal.