Ash and friends return to Mauville City, where they encounter a carnival run by Team Rocket. They let all their Pokémon out to enjoy the festivities, and Team Rocket tries to steal them. Wattson and Watt arrive to help fight off the thieves, and after the battle Wattson's Electrike evolves into a Manectric.
Everyone heads to the Mauville Gym for two practice battles. First up, May's Skitty faces off against Watt's Ampharos. Skitty is victorious with Assist, using Quick Attack and Double Slap in quick succession.
Meanwhile, Team Rocket falls into Wattson's new improved Gym traps, eventually encountering a group of robotic Raikou that they mistake for the real thing.
The second battle is Ash's Torkoal versus Wattson's Manectric. Torkoal uses Overheat too many times, and Manectric takes out the Fire-type with a Charge/Thunder Wave combo.
Watt tells May about a Pokémon Contest taking place in Verdanturf Town, so the kids make that their next destination.
Ash and his friends have finally returned to Mauville City for a pit stop on the way back to Petalburg City. Before they get ready to make any plans, Max notices a huge sign for an entrance to a carnival! They decide to check it out. To their luck, it is open, so they check out the toy stand first, mainly full of Pokémon plushies, and it's run by two suspicious looking people in a Gengar and Tauros costume. May notices the Ribbon case, and gets excited and wants to buy it. Unbeknownst to them, the people are really Team Rocket. Meanwhile, Ash and his friends send out all their Pokémon to play, and Ash's new Torkoal smogs them up as a friendly greeting, but they don't seem too happy. Ash introduces them to it, and explains that it likes to do that a lot in a friendly manner, and not to worry about it. Torkoal does it again, and it reaches Team Rocket this time. Next, they check out the soccer target game, where Brock scores a ten. The rest of them are about to take their turn, but then Ash notices his Torkoal standing right in front of the ball. Ash is excited and ready to watch it go, but Max is a little concerned that it might mess up and trip, since its body is wide and its legs are pretty short. They all watch as Torkoal lifts its legs and gets ready to kick, but instead it falls over, landing on its back.
Next, Brock has a go at the water targets. He uses the water gun that it supplies, but has Lotad and Mudkip help him with their Water Gun attacks. Max is having a shot at the ring toss game, with the help of Pikachu and Skitty. Treecko and Corphish are working on the ring-the-bell game, using Corphish's pincers and Treecko's tail, and Torkoal smogs them both again. May is playing a DDR-style game, with the help of Torchic, Forretress, Beautifly and Taillow. A silhouette of Meowth appears on the screens and shows them the moves. However, Team Rocket is standing behind the screen with a light behind him doing the moves. He pulls out a remote and presses a button. The targets of the water target game suddenly shoot out a huge wave of water, and when it clears, Lotad and Mudkip are in a cage. The mallet for the ring-the-bell game is moving by itself in Ash's hands and it hits hard enough to ring the bell, sending a net down onto Corphish, Torkoal, and Treecko! The rings for the ring toss game also start moving, and they bind up Pikachu and Skitty. And finally, Meowth bursts through the screen and grabs Beautifly, Torchic, Taillow, and Forretress in a net! Jessie is thrilled, except about having to wear a Tauros suit.
Team Rocket recites their motto from their balloon, with all the Pokémon trapped in a net underneath it. Pikachu uses Thunderbolt, Forretress uses Rapid Spin, Torchic uses Ember, Corphish uses Crabhammer, Treecko uses Bullet Seed, Taillow uses Peck, Torkoal uses Flamethrower, Beautifly and Skitty use Tackle, and Lotad and Mudkip use Water Gun, but nothing damages the net at all. Team Rocket laughs about how their expensive net works so well and float off. The situation seems hopeless, but Wattson and Watt show up in the nick of time. Wattson's Electrike's Thunder Wave does nothing, but Watt's Ampharos uses Iron Tail to cut the rope holding up the net. The net falls and all the Pokémon are safe, while Jessie yells at Meowth for not using a reinforced rope. Together, Wattson, Watt, and Ash have their Pokémon use Thunder Wave, Thunder Shock, and Thunder, respectively, which become one massive beam of electricity that zaps Team Rocket even with their electricity protection. The balloon explodes and Team Rocket blasts off. As everyone is admiring Watt's Ampharos, Wattson's Electrike suddenly evolves into Manectric. Everyone is happy for him, and Torkoal shows it by smoking them all. Ash and Wattson decide to have a battle between Torkoal and Manectric, and May and Watt decide to have a battle between Ampharos and Skitty.
The gang immediately notices that the front of the Mauville Gym looks different than it did the last time they were there. Ash is about to open the front door, but Watt yells at him not to open it. Wattson tells them that the front of the building isn't the only thing that's changed. Everyone remembers the rollercoaster ride that they got after entering the door the first time they were there, and they're not too keen on repeating that experience, especially after Wattson says that the new traps are much better than before. Inside the Gym, the first battle is between May and Watt. May starts off strong with Double Slap, followed by Tackle. Watt retaliates with Thunder Shock, which Skitty dodges, but Ampharos redirects the attack and scores a hit. He follows up with Iron Tail, almost knocking Skitty out. However, it gets back up. Ampharos uses Thunder Shock again, but right before it hits, Skitty uses Assist. It gets Torchic's Quick Attack, and easily dodges the Thunder Shock and hits Ampharos. It follows up with a Double Slap and knocks Ampharos out, giving May the win. Meanwhile, Team Rocket is standing outside the Gym. They know it must be full of powerful Pokémon, so they decide to steal them. They obliviously enter the front door, and find themselves on a roller coaster ride.
Ash and Wattson's battle begins. Torkoal uses Flamethrower, but Manectric dodges and hits with a Tackle. It doesn't do too much damage though, as both Pokémon are strong. Team Rocket is still on the ride, which they are not enjoying at all. They decide to get off at the top, but before they can a hole opens up in the ground and they free fall a very long way into water. Manectric uses Bite, but Torkoal uses Iron Defense and neither take any damage. Manectric uses Thunder Wave, but Torkoal uses Overheat. The attacks collide in midair, but Overheat is more powerful, so it pushes Thunder Wave back and scores a powerful hit on Manectric. Manectric didn't take too much damage and it still has plenty of energy left, and so does Torkoal. Team Rocket is now on a small raft in the middle of a huge pool of water, being sucked into a whirlpool. Torkoal uses Overheat again, and Manectric uses Charge. Overheat hits, but Manectric doesn't move. After Overheat, Torkoal uses Flamethrower, but Manectric still doesn't move. It finally finishes charging, and lets loose an extremely powerful Thunder Wave. Ash tries to counter with Overheat, but he already used it twice so it doesn't have much power left. Thunder Wave hits and knocks Torkoal out. Wattson is the winner. Team Rocket is out of the water, but they go through a door into a room with three Raikou. They decide to capture them and sell them, so they send out Seviper and Cacnea.
Ash and his friends say goodbye to Watt and Wattson. Watt tells May that there's an upcoming Pokémon Contest in Verdanturf Town, so the group decides to head there first. As the sun sets, they once again continue on, this time toward Verdanturf Town. The narrator comments on how Ash and May are anticipating the Badges and Ribbons they're on their way to win, as the camera pans up to a shot of the setting sun. Meanwhile, Team Rocket is still trying to catch the Raikou. Seviper uses Poison Tail on one, Cacnea uses Needle Arm on another, and Meowth uses Fury Swipes on the last one. Each attack chops off the Raikou's head. They were all robots! Of course, Team Rocket is upset, and it doesn't help when the Raikou explode. The episode ends with Team Rocket dejectedly blasting off again.