Carmen and Juni Cortez are now full-time agents of the OSS' new Spy Kids Division. They face fierce competition from Gary and Gerti, Donnagon Giggles' children. After the Giggles siblings outperform them on a mission to rescue the
President of the United States's daughter Alexandra at Dinky Winks' theme park Troublemakers, Carmen defends Gary, straining her relationship with Juni. At the OSS awards banquet, Donnagon hacks into the President's teleprompter and is named director of the OSS instead of Gregorio Cortez. Shortly after, the adults are incapacitated by a group of "Magna Men", who are after the "Transmooker", a device that can shut off all electronic devices. Gary causes Juni to drop the Transmooker in a scuffle, allowing the Magna Men to steal it. Gary blames Juni for the theft causing Donnagan to fire him from the OSS, much to Gregorio's objection. The next morning, Carmen hacks into the database, reinstates Juni's agent status, and assigns them to recover the Transmooker, which was originally assigned to Gary and Gerti. They find a mysterious island where no electronics work. Meanwhile, Gary and Gerti are rerouted to the Gobi Desert and while trying to pinpoint their position fall into a pit of
camel feces, whereupon they swear revenge on the Cortez's. Shortly after reaching the island, Carmen and Juni meet Romero, a scientist who attempted to create miniaturized hybrid animals to sell. He accidentally doused them with a growth concoction, causing them to increase in size. He also reveals that he created the Transmooker to hide his island, meaning that the stolen Transmooker was a prototype and the real one is on the island. Too afraid of the large creatures roaming around, Romero shows Carmen and Juni the way to the real Transmooker. After being informed of their disappearance, Gregorio and Ingrid begin tracking down Carmen and Juni, joined by Ingrid's parents. Carmen is captured by a flying pig, and dropped into its nest with Gerti, who tells her that Gary is genuinely evil. Juni befriends a spider-monkey, and comes across Gary who has befriended a Slizard. When Gary attacks Juni, Carmen incapacitates him. Encouraged by Juni, Romero leaves his lab and finds his creatures much friendlier than he thought. Carmen and Juni eventually find and recover the Transmooker, eliminating the cloaking around the island, and are surprised when their family joins them. Donnagon then confronts the group, takes the Transmooker and, after a fight with Gregorio tries to destroy the Cortez family with it, but it malfunctions. Gerti reveals she sabotaged it and threatens Donnagon with telling everything to her mother, which he detests. Romero arrives alongside his creatures and destroys the prototype Transmooker as well. The President, and his staff arrive on the island. He and his daughter fire Donnagon, Gary is temporarily disavowed, and Alexandra appoints Gregorio as director of the OSS. Even though he is offered a promotion, Juni resigns due to the impersonal treatment he had received by the OSS after being framed. As the Cortez family leaves the island, Romero gives Juni a miniature spider-monkey as a gift, and the island's inhabitants bid farewell to the Cortez family. During the credits,
Isador "Machete" Cortez hosts a concert featuring Carmen (with a microphone which helps her sing, and a belt that helps her dance), and Juni (with a guitar that plays itself), but realizes too late that he never put any batteries in the devices before they went onstage. When he breaks this news to Carmen and Juni, this shocks them, realizing they have musical talent. As the credits come to a close, Dinky Winks paddles to Romero's island to offer a business deal and nearly has his hand bitten off by a Slizard. == Cast ==