Power Play came out on April 5, 2011.
The book opens with Charlene, Amanda and Finn at a roller-coaster simulator. Charlene designs their rides. Finn and Amanda are put through an insanely dangerous simulation; they begin to suspect Charlene of messing up with them. After a Kim Possible phone mission from Wayne, Philby, Maybeck and Finn decide that Charlene is under a spell by the Evil Queen from Snow White and that a kiss will break the spell. Maybeck tries, but fails, Charlene not letting him kiss her. That night Charlene is crossed over unexpectedly and Finn and Phliby go to rescue her. Philby manages to kiss her almost unwillingly and the spell indeed breaks. Finn figures out that the Queen has more than Charlene under a spell.Willa is crossed over, but this is not supposed to happen. While she's crossed over, Willa is saved from drowning by Ariel from The Little Mermaid and finds out that the "characters" from all Disney movies are in fact real, not Cast Members. However, the others find out they can't get to her because the Overtakers cut Philby's connection to the DHI server. Finn, Maybeck, and Philby sneak in to the server room in the Utilidoors to get back the connection, which they accomplish. That night, Finn and Maybeck cross over and rescue Willa. When they're brought back, they think the Overtakers are trying to put them all in Sleeping Beauty Syndrome to make them useless.
Later on, the Keepers decide that the Overtakers, the Evil Queen from Snow White and Cruella de Vil from One Hundred and One Dalmatians especially, are trying to free Maleficent and Chernabog from their prisons. The Evil Queen puts a spell on Finn, but believing he was all clear (a pure DHI) when she did, Finn thinks he's safe.
The spell, which was intended to eventually make Jess unconscious, messes up due to Finn being partially DHI and the fact that Jess is just a friend. Finn kisses Amanda - whom he has feelings for - and she falls into a coma. Because the spell included the words "reverse the curse" and Sleeping Beauty's sleeping spell was started by being pricked by a spindle, the Keepers try to get Disney spindles for Amanda. She doesn't wake up. Philby crosses Amanda and Finn over. They meet Minnie and Pluto. They get Amanda's DHI pricked with the cotter of the waterwheel on Tom Sawyer Island and the spell is broken. They are manually Returned. Over the course of the next events Finn realizes how the Overtakers are going to break Maleficent and Chernabog out. Because they engineer a power outage, the prisoners' doors open. Then they use the security cameras to project DHIs of sleeping Chernabog and Maleficent into the cells. The villains escape by wearing guards' uniforms and walking out. Finn gets to the prison and meets Wayne, but it's too late to prevent the two escaping.
The book ends with the Keepers, Ariel, Amanda and Jess realizing that a picture Jess drew earlier depicts Captain Peter Roseman of the Disney Magic, a cruise ship, the site of the next Keeper installment. Ariel reveals that Mickey Mouse is meant to be the characters' leader, but that he's missing. Finn asks Ariel to keep the Return fob button safe, and she agrees. Then he presses the button and they all Return.