As the episode opens, the heroes are approaching Lilly of the Valley Island, the site of the upcoming Sinnoh League. The island is populated with trainers and media reporters, all bustling with excitement for the upcoming tournament. In the Pokémon Center, Ash approaches the front desk and registers for the Pokémon League. He receives a key for his room in Trainer Village, and Nurse Joy wishes him luck.

Around the corner, Team Rocket plans on poaching all the powerful Pokémon in the Pokémon Center, turning them in to the boss, and becoming rich.

Meanwhile, the heroes are exploring the area; Dawn notes how different everything is from the Grand Festival when Conway suddenly appears from behind. In the room, Ash finds that Professor Oak has left him a gift. In return, Ash gives Professor Oak a call to greet him and see how all his other Pokémon are doing. Ash asks for some of his different Pokémon, and says he will send five Pokéballs first. Ash inadvertently gives his Pokéballs to Jessie of Team Rocket disguised as a Pokémon Center worker, and she ends up stealing the Pokémon with James.

Moments later, the real clerk behind the desk appears and asks how she can help Ash. Ash notices that something is wrong, and runs outside to find the people who took his Pokéballs. He finds out it’s Team Rocket as they drive off with Ash’s Pokéballs. Ash tells Pikachu to use Thunderbolt on the getaway vehicle, sending Team Rocket blasting off. Unfortunately, Ash’s Pokéballs go blasting off as well.

The heroes quickly manage to find the Pokéballs a short distance away, but all five Pokéballs are empty. After looking for a little while, the heroes manage to find Corphish walking around and Totodile playing in a fountain. In a nearby kitchen, Ash finds Snorlax eating all the food. Ash quickly tells Snorlax to return to its Pokéball. As he moved on to the next Pokéball, he noticed that it didn’t belong to the Pokémon that he asked Professor Oak to send.

Back at Professor Oak’s lab, Professor Oak notices that Heracross is still at the lab trying to drink out of Bulbasaur’s bulb. Professor Oak swears that he sent Heracross to Ash earlier, but realizes that he may have made a mistake.

Meanwhile, the heroes run through the forest looking for the remaining two Pokémon when they run into Barry. Barry says that he was recently hit in the head by a spicy Pokémon – Ash realizes that it is one of his Pokémon, Bayleef. When Bayleef sees Ash, it jumps on him, showing its affection.

Over with Team Rocket, Ash’s Cyndaquil runs into one of Team Rocket’s machines as they try to catch it. Cyndaquil manages to avoid all the traps, but is soon cornered against a building. Cyndaquli fires up its back and uses Flame Wheel to roll out of the way of all the other traps, setting a tree on fire in the process. The smoke from the fire alerts the heroes and they start running towards the smoke. They make it just in time to save Cyndaquil; Dawn tells Piplup to use Hydro Pump and Ash tells Corphish and Totodile to use Bubblebeam and Water Gun to put out the fire. After seeing all the Pokémon, Team Rocket tries to catch them all, but their plan fails when Bayleef uses Razor Leaf to cut off all the machine’s arms. Ash attempts to finish off Team Rocket by telling Pikachu to use Thunderbolt, but soon finds out that Team Rocket’s machine is electric-proof. From the inside of the machine, Meowth pushes a button and switches out its arms. Ash tries to slice off the arms again with Bayleef’s Razor Leaf, but Team Rocket uses a chainsaw to intercept the leaves. Ash sends out Snorlax to use Body Slam, which brings the machine down to the ground. To finish it off, the water Pokémon use their water attacks again while Pikachu uses Thunderbolt to take advantage of the water conductivity. Unfortunately, the machine still stands strong.

From nearby, Cyndaquil emerges and uses Flamethrower on the machine, but the machine is fire-proof as well. The machine uses Rapid Spin to send the flames falling back down to Cyndaquil. The machine then chases Cyndaquil with drills and revolving saws and goes to grab it, but right as the machine makes contact with Cyndaquil, it evolves into Quilava. Quilava runs near the machine and uses a new attack, Eruption. This sends Team Rocket blasting off again.

Back in the Pokémon Lab, Ash tells Professor Oak of the recent event, and asks for five more of his Pokémon. Ash then gets frozen by his Glalie and melted by his Torkoal, watches his Noctowl fly as he gets body slammed by his Muk, and observes his Donphan use Rollout on a pile of rocks.

As the episode comes to a close, the opening ceremony takes place as the torch gets lit for the league. In the distance, Ash sees Cynthia; in the crowd of trainers, he sees Nando, Conway, Barry, and Paul. The first round match-ups are revealed, and Ash sees that he will be battling Nando first.