The episode starts off at night with Night Ninja training his Ninjalinos at the museum. The Ninjalinos follow the steps for a very special ninja move, only to keep messing up. They also laugh at Night Ninja when he loses his balance and falls down into the fountain. Annoyed, Night Ninja begins to scold the group, until he sees something from the book that he is using for training purposes. Getting an idea, he tells the Ninjalinos that the lessons are over, and the group happily runs off as the villain plans something evil.
The next day, Connor, Amaya, and Greg walk to school when they see the streets in a messy state. Within the mess is a trail of Ninjalino footprints. That night, the PJ Masks take a look at the PJ Picture Player and see the Ninjalinos acting erratically, performing strange movements and wrecking multiple objects around the town.
The PJ Masks drive over to the museum using the Gekko-Mobile, where the Ninjalinos are located. As the others stumble while trying to do some skills, a Ninjalino approaches them, and explains that they have lost all their ninja skills while resting for a bit. In addition, they cannot ask Night Ninja to retrain them because he is, suspiciously, for some reason, nowhere to be found.
Suddenly, the Ninjalinos get an idea; they want the PJ Masks to retrain them instead. Catboy refuses to at first, feeling that they are just going to go back to being bad, but Gekko decides that they could use this chance to place their ninja energy into good skills, feeling that everyone deserves a second chance. Catboy agrees to give it a try, and they tell the Ninjalinos that they will help them out as long as they promise to listen to the team and use their skills for good.
Catboy and Gekko head over to the park to train the Ninjalinos. From there, Gekko offers them new activities they can try. He has the group try out some circus skills using a tightrope, practice some ballet moves, and do some yoga poses. The Ninjalinos perform the skills flawlessly, showing that they have great potential. They still stumble occasionally, though. In addition, while Catboy is impressed by the potential the Ninjalinos have, he is still uncertain about them wanting to try new things.
Meanwhile, Owlette goes into the museum to investigate why the Ninjalinos lost their powers. She finds the book Night Ninja had the other night and sees that it is covered in Sticky Splat. She turns to the page where Night Ninja was on, and finds out that he stole the Ninjalinos' powers. He did this by obtaining a statue, which gives the person in possession of it the powers of other ninjas.
Suddenly, Night Ninja appears and bombards Owlette with sticky splats. With the Ninjalinos’ powers and the statue in his hand, he is now powerful and wants to take the museum to Mystery Mountain with his new powers in order to serve as his new pagoda. Owlette tries to stop him, but Night Ninja gets out of her way and uses his Ninja fingers on her to send her into another part of the museum.
Once she is out of the way, he goes on top of the museum and uses the power on the building. Locked in, Owlette contacts Catboy and Gekko for help.
As the Ninjalinos practice their yoga poses, they, Catboy, and Gekko see Night Ninja lifting the museum while creating a sky portal to Mystery Mountain. Catboy attempts to use his Super Cat Stripes to tie to the museum, but the building is too high, and they do not have Owlette to fly them up there. However, even though Night Ninja stole their ninja skills, the Ninjalinos plan to use their newly learned skills instead. They are angered by the information that Night Ninja used a special statue to steal their powers, so they decide to work with the team to get the statue and stop the villain.
Going on top of headquarters, Catboy is able to tie his Cat Stripes to the museum. He and the others quickly get on there, the Ninjalinos using their circus skills to skillfully cross the tightrope. Once everyone is on, Gekko and the Ninjalinos quietly go on top of the building, and he tells the group to perform a ballet dance. The Ninjalinos do so gracefully, and grab Night Ninja’s attention. Gekko then tells them to perform their yoga poses, and the group trips the villain and knocks the statue out of his hands.
The portal vanishes, and the museum falls, but with the statue in the Ninjalinos’ hands, the group gets their ninja skills back, and they use their ninja fingers to put the building back where it belongs. The PJ Masks cheer for the Ninjalinos and commend them on a job well done on their newly acquired skills, delighted that they are not so bad after all.
As the Ninjalinos destroy the statue, Night Ninja walks up and attempts to apologize to them, asking if they could forget any of this ever happened. The group responds by sending the villain into the fountain, then lifting him up in the air for a while. Although the Ninjalinos did turn nice, they still have a bit of a naughty personality left in them. Nevertheless, the PJ Masks do their victory chant while Night Ninja is still in the air, screaming for help.
Use the new skills that you've learned.
The PJ Masks can finally understand the Ninjalinos' blabbering language.
This is the first time Night Ninja turns against his Ninjalinos by stealing their powers.