Thanks to an ability programmed in their virtual avatars by the Imagineers of Disney in the DHI technology the five teens are transported every night into the park as holograms while they sleep.
They find themselves in the middle of a war against various Disney villains called the Overtakers, led by Maleficent from Sleeping Beauty, and they must stop them from taking over the park and then the world.
After Wayne, their friend, mentor, and head Imagineer, disappeared during the events at Animal Kingdom, Finn, Philby, Willa, Charlene, and Maybeck suspect the worst.
Their search takes the Keepers, plus Amanda and Jez, into Hollywood Studios and Epcot, where they must fight through puzzles, giant snakes, and deal with Maleficent and her friends while discovering new truths about themselves.
For the five teens who modeled as Disney Hologram Imaging hosts, life is beginning to settle down when an intriguing video arrives to Philby's computer at school.
It's a call for action: the Overtakers seem to be plotting to attempt a rescue, led by the Evil Queen and Cruella De Vil, of two of their leaders, both of whom the Disney Imagineers locked away following a violent encounter in Epcot.
Spring break for the Keepers means a DHI cruise from Florida through the Panama canal to Los Angeles, with stops in exotic locations—including Castaway Cay, Disney's private island.
The five Kingdom Keepers and their core friends have uncovered a startling truth: Maleficent and the Overtakers are plotting a catastrophic event that could have repercussions far beyond the world of Disney.
The Keepers have enjoyed three years of relative quiet, but as they get ready to graduate high school, the Overtakers, and a nightmare they left buried in an ancient temple in Mexico, are rising again.
Written with Brooke Muschott (as Jess) and Elizabeth Hagenlocher (as Mattie),[7] this adventure focuses on Amanda, who is searching for the missing Kingdom Keeper Finn Whitman.
A father and son, who were fans of the books, initially suggested the concept of King Arthur's Carousel being a means of time travel, and the protagonist using it to go back to Disneyland opening day.
The Keepers eventually discover that the music box in Walt's apartment opens an anomaly on a horse on King Arthur Carousel, allowing its rider to travel through time.
In the second book, the Keepers have successfully arrived at Disneyland's Opening Day in 1955, there to track down Walt's pen and ensure that it is in the right place in the future.
In the third book, Finn and the other Keepers, now joined in the past by Amanda and Jess, have decided to make use of the fact that they cannot yet return home and stop Hollingsworth from creating the Overtakers.
Pearson indicated to Wendy Lefkon, Disney Publishing Worldwide editorial director, that he found that each attraction and ride "tells a story, with a beginning, a middle, and the end".