At the Vertress Conference, Ash battles an unnamed male Trainer with his Scraggy. Scraggy defeats the opponent's Darumaka using Headbutt, leaving Ash to proceed to the last 16 Trainers. It then shows the battles of Ash's rivals. Stephan's Sawk defeats a Gurdurr and Stephan wins. Cameron wins with his Ferrothorn against an Amoonguss and Virgil wins with his Glaceon against a Reuniclus. Afterwards, the central screen shows the match-ups for the last 16. Much to Ash's shock, he finds out he has to battle Stephan.
After the second round, the Trainers begin to rest for tomorrow. As Cilan, Iris and Bianca walk through town, Bianca immediately realizes that there's an Ice Cream stand selling Casteliacones and goes ahead to buy some. Axew suddenly notices a balloon floating by and runs after it. Meanwhile, Ash and Stephan are arguing who will win their battle. Cameron becomes excited because there will be fireworks that night, and he and Riolu run off to set up a tent in the open air to enjoy the fireworks to the fullest. Stephan tells Ash that he will show him how strong he really is and walks off. Ash then meets up with Cilan and Iris and Pikachu notices Axew is gone.
At that same moment, Axew still chases the balloon but finds it has flown away. He then realizes he got lost and because there are so many people, he can't see where Iris and the others are. Axew then sees a bunch of people celebrating for Russet, a participant of the Vertress Conference, for making it to the first few rounds. As Russet's celebrating squad walks by, Axew follows and an old lady of the squad notices Axew and grabs him. Meanwhile, Ash, Iris and Cilan are still searching for Axew.
Axew becomes dizzy because the woman that has taken him away runs at a fast pace. At the Vertress Stadium Ash and his friends are searching Axew using the surveillance camera system. Suddenly, Iris sees a recording where Axew is taken by the arm by an old woman. In the city, Bianca is eating a Casteliacone. She notices Axew walking all alone with a costume on. Axew tries to reach Bianca, but is taken away by Russet and his supporters once again. Meanwhile, Cameron and Riolu are setting up their tent near a lake. Their camp is accidentally destroyed by Russet and his supporters, however. Ash, Iris, Cilan and Virgil meanwhile are still in search for Axew. They meet up with Bianca and she wants to give them Casteliacones, but accidentally knocks Ash away in the water. Bianca then tells that she has seen Axew. The group decides to use their Pokemon to search for Axew. Ash sends out Pikachu, Oshawott and Scraggy while Iris sends out Emolga. At that same moment, Axew and Russet and his family and friends are picnicking and the group celebrates the fact that Russet made it to the last 16. Axew notices a girl giving her Lillipup food, which reminds him of Iris.
Meanwhile, Pikachu, Scraggy, Oshawott and Emolga are still in search of Axew. Whilst Pikachu and Scraggy ask a Stoutland for help, Oshawott notices a bunch of apples given to some wild Trubbish by a shopkeeper. The group of Trubbish notices Oshawott coming and hide. Oshawott then proceeds to eat all of the apples. Emolga and a wild Swoobat manage to find where Axew went. As the Pokemon prepare to leave, the shopkeeper that gave the apples to Trubbish notices that Oshawott ate all the apples and that Oshawott got overweight. Elsewhere, Axew runs away from the group of supporters to find Iris. At that moment, the Trubbish realize that Oshawott ate all of their apples and begin to cry, and a Garbodor appears, consoling them. It and the Trubbish then head on their way to search Oshawott. Meanwhile, Cameron and Riolu manage to repair their camping spot. Iris and the others come by and find the hat that Axew wore earlier and countinue to search, destroying Cameron's camp once again. Somewhere else, in a forest, Axew cries that he got lost. But Pikachu and the other Pokemon manage to find him and they reunite. The Garbodor and Trubbish arrive, however, having come to get revenge for Oshawott eating all the apples.
Elsewhere, Bianca and Virgil are still in search of Axew and the other Pokemon. They meet the woman who gave the wild Trubbish behind her store the apples that Oshawott eventually ate. She explains that there was a stuffed Oshawott with a Pikachu and Emolga and she leads Bianca and Virgil in the direction they went. At the forest near Vertress City, Axew and the other Pokémon run away from the angry Garbodor and Trubbish. Pikachu tries to ask them why they're doing this, but Gardobor responds by attacking them with Gunk Shot. Pikachu and the others end up at a cliff with only a deep abyss beneath them. Meanwhile, in the forest, Iris, Ash and Cilan find another piece of cloth Axew wore earlier. Then they suddenly hear a group of Pokémon screaming, which they recognise as the screams of their own Pokémon. At the cliff, Oshawott tries to reason Garbodor, but Gardobor reveals to Pikachu, Emolga and Axew that Oshawott ate all of the apples that were meant for the Trubbish. Oshawott tries to apoligize, but Garbodor ignores him and attacks once more using Gunk Shot. Oshawott quickly protects himself using his scalchop. Suddenly, Ash, Iris and Cilan arrive at the scene. But Garbodor once again attacks the group of Pokémon with Gunk Shot and sends them falling of the cliff. Then, out of nowhere, they are saved by Virgil's Espeon using Psychic. After Virgil and Bianca inform Ash and co. that Gardobor and Trubbish are attacking Oshawott because he ate their apples, Ash tries to stop Garbodor and tells it they're sorry for this incident. However, Garbodor still refuses the apologies and attacks them once more with Gunk Shot. But Virgil stops the attack in time using his Umbreon's Shadow Ball and then uses a Soothe Bell to calm Garbodor down.
Back at Vertress City, Ash and co. bring a large supply of food to Garbodor and the Trubbish and have Oshawott apologize. At that moment, the fireworks show starts at Vertress City and everyone in town is watching. Ash, Iris and Cilan arrive at the lake near the city where Russet and his family and supporters are. The old lady who took Axew with her earlier notices that Axew got reunited with his Trainer.
The next day, the Vertress Conferece continues and the first battle is Ash against Stephan. Stephan sends out Liepard, which Ash scans. Ash is then about to send his Pokémon as the episode ends.