Aniello, Teresa, Gennaro, Raffaele and Sasà, the Wonderboys, are about to be evicted from their homes by the Old Hag. Their last chance to stay together is to find the Maradona figurine that their idol, Tonino Wonderboy, stole from her. To retrieve it, they must venture into underground Naples, making their way through legends and dangers.
In underground Naples, the Wonderboys team up with Tonino and make an incredible discovery. Meanwhile, the Old Hag and her henchmen are on their heels, equally determined to get a hold of the Maradona figurine. Above ground, the parents are increasingly concerned about the disappearance of their children.
The Old Hag has a plan and drags Clemente to a charity event at Nino D'Angelo's mansion. Meanwhile, underground, the adventure of the Wonderboys appears to be over: Tonino has been captured and Chihuahua, after retrieving the figurine, is escorting the kids back above ground. However, Clemente betrays the Old Hag and joins forces with Antonia, who has arrived at the party with the parents.
The Old Hag is trying to track down Clemente. Antonia and Tonino, while searching for a way out from the underground to lead the kids to safety, stumble into a dangerous solfatara. Meanwhile, Chihuahua is dismissed by the Old Hag, and Enzo searches for information about the mysterious figurine.
Tonino and Antonia sneak into the Archaeological Museum of Naples to discover more about the photo. They must hide from the Old Hag, who has also arrived at the museum. While Teresa manages to get to the Fontanelle Cemetery, the parents desperately try to contact the Wonderboys, who are still underground and in danger.
Naples is preparing for New Year's Eve celebrations, while the Wonderboys, Clemente and Tonino are determined to get their hands on the treasure. In the meantime, after seeking help from the police, the group of parents begins to believe in the magic of Naples.
