Ash and friends are passing through a seaside town, and notice a boy who is giving advice to his Pokemon. This Pokemon is a Wobbuffet, the "patient" Pokemon who likes to live in dark areas.
Introductions are made and the boy says his name is Benny. He's taking his Wobbuffet to the Pokemon Swap Meet, which is an annual event where trainers trade their Pokemon. Misty wonders why he wants to trade and he says he trained the Wobbuffet hard but now wants to train a different Pokemon. He takes them all to the meet.
Team Rocket is in town as well; James waters his Victreebell and Jessie washes her face only to get messed up again when Lickitung licks her. Meowth tells them about the swap meet and they decide to go and steal some Pokemon. They run off, but are being followed by a familiar Snubbull... In the street, people are running away from a herd of rampaging Tauros. Brock asks someone what's happening and learns that this is a tradition called the Running of the Tauros, and the person brave enough to run in and touch the horns of a Tauros is awarded a prize by the mayor. Ash thinks about trying it, but as the herd runs closer he changes his mind.
The Tauros all enter a stadium where their trainers battle them against each other. Ash wants to battle too, and calls Professor Oak to tell him to send his Tauros. Prof. Oak tells him he already has six Pokemon and needs to send one of his other ones back, and asks to have Heracross to study. So Ash trades Heracross for Tauros, and heads back to the arena to challenge a trainer who has been unbeaten.
Jessie and James are in the arena disguised as waiters, selling food and watching out for Pokemon to steal. Ash's Tauros defeats its opponent, and Ash and friends go out on the town. Two young trainers trade their Pokemon with the help of an exchange machine. Benny wants to see if Ash will trade his Tauros for Wobbuffet, but several people also ask Ash if he wants to trade his Tauros, and he refuses. Then Benny tries to trade his Wobbuffet to a trainer with a Scyther but is turned down. Ash and the others offer to help him find someone who is willing to trade.
TR is disguised as scientists and saying that their Pokemon exchange machine will raise the levels of the Pokemon that are traded with it. A large crowd of people gathers, all wanting to use it. Meowth is inside the machine, swapping the Pokeballs with empty ones. Snubbull passes by, still searching, but doesn't see TR in the crowd.
As Misty is looking for someone to help Benny, her Psyduck comes out of its Pokeball on its own. She tells it to get back in before she gets any ideas to trade it. A few people ask her to trade but she refuses and runs away. Meanwhile, Ash and Brock have persuaded a trainer with a Stantler to trade for the Wobbuffet.
James is looking for a place to buy lunch, when a pushy salesman tries to sell him a Magikarp. He realizes that this seems familiar and remembers the time he bought the Magikarp on the Saint Anne... from the same salesman! Furious, he chases the salesman down the street.
Benny and the Stantler trainer are at an exchange machine and are about to trade when the other trainer sees someone walk by with a HootHoot and changes his mind about the trade, saying he would prefer a flying Pokemon. Benny is very disappointed.
Still chasing the salesman, James bumps into Jessie, knocking her back. She falls on the exchange machine, one of her Pokeballs lands in the machine and gets swapped with Benny's Wobbuffet! Unaware that this happened, she grabs her Pokeball back and runs off to find James.
Meowth finds Jessie and James, and tells them that the people have realized their machine was a phony. The crowd, including our heroes, approaches them but Meowth uses a device that ties them all up. Then TR gets their balloon and uses a vacuum to suck up the rest of the trainers' Pokeballs. Ash gets an idea and tells everyone to use their Tauros. The Tauros attack TR, throwing them away, and a bag with the Pokeballs in it drops out of the balloon. Unfortunately the Pokeballs all turn out to be empty; TR still has all the real ones.
Ash confronts TR and Jessie throws a Pokeball, expecting it to be Lickitung, but gets Wobbuffet instead! She realizes that it had been swapped by the machine, and tries to get it to attack but it won't. James reads from a book that Wobbuffet can't initiate attacks, and she gets angry.
Ash attacks with Chikorita but Wobbuffet has a Counterattack ability that reflects the attacks back at Chikorita. Ash recalls Chikorita and sends in Pikachu. Wobbuffet is unable to deflect Pikachu's Thunderbolt and TR (plus Wobbuffet) goes blasting off again.
Our heroes return to town and give the Pokeballs back to their owners. Benny finds them, he's very happy and wants to thank the lady who traded the Lickitung for his Wobbuffet. Misty says they haven't seen her, so Benny just yells out that he promises to take good care of Lickitung. Meanwhile, TR is stuck in a tree. Jessie consoles the Wobbuffet by saying that they'll beat those kids someday, they'll just have to be patient.