Before the Grand Festival, Dawn and Ash train. Piplup uses Whirlpool and Gible Draco Meteor. This fails and lands on Piplup. While Brock made lunch, Piplup spins and uses BubbleBeam. Dawn gives him some rest and sends Togekiss, who uses Sky Attack. As Piplup is resting, two bright eyes are seen in a nearby bush. Piplup comes to lunch and eats a lot of food, some of which is not his own. Suddenly, Piplup comes and fights with the one on the table. Seeing how they cannot surely tell which is the real one, Gible's (failed) Draco Meteor lands on the real Piplup.
However, they soon spot two Togekiss. Dawn calls the real one back in the Poké Ball. Suddenly, there is the problem with Pikachu. Ash picks one, but gets zapped by the other Pikachu. He picks the other and gets zapped by the other one. Piakchu makes silly faces, but there is no difference and there is another Piplup, which gets in the fight with the one in Dawn's hold. Suddenly, Gible gets in the fight with its counterpart. Suddenly, a woman comes and orders the counterparts to cool down, which transform back into Ditto. They meet up with the woman, Narissa, whose nickname is Rissa. Dawn and Ash think it is an interesting nickname, but this gets Narissa riled up, as she is also called the Rumbler.
As Narissa confesses she is a trainer, Ash thinks she is like her, but gets insulted by being called a noob. She admits she has been on the journey a month and has not won a single badge, making Ash and Dawn not impressed by her. Meanwhile, Team Rocket hear that and Meowth believes that the boss would be saved by having Ditto transform into powerful Pokémon. Ash proposes a Pokémon battle, which Narissa accepts, using her Ditto. Narissa has her teal Ditto and Ash sends Infernape. Ditto copies Infernape and uses its moves. Inferape uses Flame Wheel and Ditto collides with the same move. Infernape uses Mach Punch and Ditto collides with it using the same move, but Ditto is defeated.
Narissa sends her other Ditto, while Ash calls his Infernape back and sends Pikachu. Instead of copying Pikachu, Narissa chooses Piplup to copy. Pikachu uses thunderbolt, which electrocutes Ditto. Narissa picks Pikachu to copy, so Ditto transforms into him. Ditto uses Iron Tail, but Pikachu shrugs it off. Pikachu uses Quick Attack and Ditto Volt Tackle, causing Ditto to be defeated by the collision. Narissa gets upset and wants to get in fight with Ash. Brock and Dawn do not think it is a wise move, but Narissa remembers she won a battle; a Zapdos passed by and the Ditto transformed into it, causing the opponent to flee. Though others do not think it was a win, Narissa does not care any other way. Brock talks with Narrisa, giving her a piece of his mind; she needs to study Pokémon more. While Narissa continues to be ignorant, Brock tells her she needs to do that or she will not be a trainer.
Narissa cries, as she tried to act tough, which is why she dressed up as Flint of the Elite Four. Brock tells her that while Ditto can copy moves, their strength is not the same. Brock advises her to study and it should be fine. Brock makes a review of her battle; her Ditto could have first transformed into Piplup, which would be a good advantage against Infernape. Brock then explaines that Pikachu knows different type moves to get a more advantage. To test her, he is going to use his Happiny against her Ditto. Ditto use Pound, so Happiny uses Pound and sends them away because of her impressive strength. They attempt the same using Sudowoodo. Ditto use Hammer Arm and Sudowoodo retaliates using the same move. Suddenly, Ditto get captured by Team Rocket.
Jessie sends Seviper, who uses Haze and they disappear. Ash sends Staraptor to scout. When the Ditto are let out, they copy Meowth and Wobbuffet. It did not took much for the gang to find them. James sends Carnivine, who uses Bullet Seed, though Ditto transform into Staraptor and use Aerial Ace, which dodges Bullet Seed and attack Carnivine. Jessie sends Seviper, so Ash sends Gible, allowing Ditto to be transformed into it. Ditto digs, while the other uses Quick Attack on Seviper. The Ditto transform into Pikachu and they all use Thunderbolt, which makes Seviper and Carnivine unable to battle. Narissa promises to act less tough and asks of Brock if he can visit him again. Brock agrees and when he spots a girl, he flirts with her, but gets stabbed by not one, but *three* Croagunk. Narissa goes away, annoyed by all this. Later, the heroes find themselves at Lake Valor, for Dawn's Grand Festival.
This is the first episode where Gible intentionally fires Draco Meteor on Piplup.
When Team Rocket throws the net on Ditto 1 and 2, they are still transformed into Sudowoodo, but in the next scene, they are ditto, despite not shown transforming.
In the original Japanese, the two Ditto speak human language when they've transformed into Meowth. This was changed in the dub, where Meowth still speaks human but the Ditto say "Meowth".