The episode starts off at night with the PJ Masks watching the Wolfies play around in the trees. The pack swings on the branches as fast as they can, and they howl themselves up in the air and into a dumpster. They come out unharmed, though. In addition, they notice that they have traveled to where the Mystery Mountain portal is located.
The next day, Connor, Amaya, and Greg walk around the town, enjoying the Wolfies’ personalities, when they see Wolfy prints leading to the end of the alleyway. The pack has traveled to Mystery Mountain again and must have stayed there since last night. The PJ Masks transform later that evening and head off to Mystery Mountain on their PJ Rovers to see what antics are taking place.
The Wolfies travel halfway up the mountain to where the cave is. They howl into it and let themselves be hit by the sound waves echoing out. As they howl, An Yu hears the commotion from the pagoda and flies down to the pack’s location. Their sonic howl echoes out and hits her, though, sending her flying down the mountain. Fortunately, the PJ Masks arrive just in time to catch her.
The Wolfies run down, Kevin explaining to An Yu that they did not mean to howl at her. However, she is angry at them, knowing that they are causing trouble on the mountain. In response, the group uses their sonic howl on her and the PJ Masks. The team gets hit, but An Yu escapes and plays a tune on her flute. As a result, the Wolfy Kids get hypnotized. She explains that she found some songs in a book she read that can be used to control animals, such as the hypnotized villains. Using the tune, she can train them into her loyal mountain guard dogs for the night.
Behind the bamboo stalks, Night Ninja spies on the group and overhears the conversation. He plans to get in the pagoda and take over Mystery Mountain again, but he needs to get the pack on his side. Therefore, he has his Ninjalinos steal An Yu’s songbook, while he makes himself a flute.
The PJ Masks and An Yu walk to the top of the mountain with the hypnotized Wolfy Kids. Reaching the pagoda gates, the group sits and stays as An Yu commands and places her tune book on Rip’s head. She is pleased at the progress, but Gekko is unsure if this is the right way to train them, feeling that it is not nice to control them, even though it was not nice of the villains to howl at the heroes. Owlette responds by saying that it is just only for the night, and possibly, the pack could maybe learn a couple of things.
Still, Gekko like their wild side, and imitates their howl. This makes the Wolfies snap out of their trance, though, but only for a moment. An Yu plays her flute again before they could do their sonic howl, and everyone continues walking. They do not notice the tune book that has dropped on the floor, or one of the Ninjalinos sneaking by to grab it. Meanwhile, Night Ninja cuts one of the bamboo stalks and creates a flute out of it.
A few moments later, an obstacle course is set up for the Wolfies to continue their training. An Yu continues playing her flute to keep them in control when the Ninjalinos fire Sticky Splats with their catapult. The pagoda under siege, she commands the group to howl the splats away. The projectiles land outside the gates, one hitting the catapult, causing it to activate and fling one of the Ninjalinos.
Night Ninja soon finishes rehearsing the tune he needs to play. He flings himself over the gates, and avoiding the dragon tongue splats, he plays a new tune with his flute before the Wolfies can attack him. The pack is hypnotized by his sound, and they are put under the villain's control. An Yu plays her tune to keep the group under her control, but Night Ninja retaliates, and the two verse each other in a flute confrontation, fighting over control of the Wolfy Kids.
With the chaos happening, Catboy attempts to stop Night Ninja by using his Cat Stripes to tie him up. The villain get out of his way, and Howler spins him around, causing him to fall on one of the spring booby traps. Owlette saves him, but Night Ninja uses this chance to throw a Sticky Splat at An Yu’s hands. He has the Wolfies howl at the heroes, and the group is sent flying outside the pagoda gates, causing the Ninjalinos to retreat.
Gekko tries opening the gates with his Super Gekko Muscles, but they do not budge. Owlette attempts to fly in, but she is howled out. Since the Wolfies will not let them in, An Yu needs her hands and flute to be rid of the splat so she can control them again, playing as loud as she can. Catboy and Owlette both argue with An Yu that Night Ninja has his own flute, and he is just going to play loudly as well. Gekko stops the argument; he explains that the Wolfies are not bad; they can do the right thing. All they need to do is to get them back to their Wolfy ways, not by using An Yu’s flute, but by using their original personality.
Night Ninja relaxes on the pagoda’s stairs with the Wolfies next to him. He prepares to have them open the doors of the pagoda when they hear Gekko howling. The villain plays his flute in response, but the group opens the gate to take a look at what is going on. Gekko is pretending to be a Wolfy. Since the heroes have the pack’s attention, Catboy and Owlette also pretend to be Wolfies, and the PJ Masks play around. Intrigued, the Wolfies join in on the fun.
Meanwhile, An Yu frees her hands and flute from the Sticky Splat. She is about to play to gain back her control on the Wolfies, but after witnessing the group playing around, she realizes that they are not so bad after all. She decides to participate in being a Wolfy herself, and the heroes howl. Night Ninja, seeing all the commotion outside, tries to gain back his control over the Wolfies, but to no avail. The Wolfies snap out of the trance, and they are back to their regular selves. They destroy the bamboo flute and send Night Ninja down the mountain with their sonic howl.
The Wolfy Kids thank the PJ Masks and An Yu for freeing them under anyone’s control, not feeling like themselves. They apologize for the cave howling incident, while An Yu apologizes for controlling them. She gives them an invitation to come back to the mountain as they wish, and the Wolfies happily run around her. She also thanks the PJ Masks for their help, especially sharing a laugh at Gekko’s comment about doing a great wolf howl. Everyone now alright with each other, they proclaim the PJ Masks signature victory phrase and howl together.
Don't change others for who they are or what they are.
It is not nice to control others.
Howler and Rip join the PJ Masks' victory pose for the first time.
This is the second time Kevin joins the PJ Masks' victory pose.