Five kids are chosen to become DHIs, or Disney Hosts Interactive. Their hologrammed selves are used to tour guests around Walt Disney World and provide information. Finn is one of those five, but he soon realizes this DHI business is a lot more complex than he originally thought. He and the other four kids are able to enter the park at night, after closing hours, in their DHI forms. They need to stop the Overtakers from, essentially, taking over the park and the world beyond it.
The plot was interesting, but something about this book left me feeling a little dissatisfied. I'm not really sure what it was, but the story was still an entertaining read. It has some puzzles to be solved, but it's a little confusing at first to understand what the protagonists are expected to do, and Wayne – their and our main source of information about the villains and the plot – seems unhelpful more often than he is helpful. He has information that could be really useful to the kids to saving this park, but he withholds it while insisting over and over that Finn and the others are the only ones who can save the park.
The main protagonist, Finn, is a fun guy. He and the others seem believable, despite moments when things felt unrealistic for them to be doing, and they're nicely characterized and unique from each other. While we see the adventure through Finn's eyes, we jump to other POVs for a short time, but usually don't return to them again. The main villain of this book isn't developed a lot, but she is still a creepy villain, producing cold wherever she goes, has abilities revealed later on, and is a character almost anyone would recognize.
(Note: I did not keep up with this section as I should have, so it may be lacking a few minor details. Overall the book was clean, however.)
Violence/gore: Finn is burned with a laser (minor), and Finn lasers down mechanical pirates. The characters are attacked by and receive minor injuries from dolls in an attraction, which might get a little scary. Any other violence isn't described in great detail at all.
Other: Finn lies about sneaking into Disney World without permission. The kids sneak into areas they probably shouldn't be.