There's a problem in the park in Cerise's Laboratory. The food that was to be given to the Pokémon being taken care there has disappeared and the Pokémon have started to fight. Ash & Goh decide to stay there to catch the culprit but as time passes, the fighting gets worse and Cascoon starts to show signs of evolution. As Goh's Golurk goes to protect Cascoon, the seal on its chest comes lose and it goes out of control. Will they be able to find the culprit? (thetvdb.com)