Our heroes stop at a Pokémon Center on the way to Cyllage City, where they meet a Trainer named Lena and her little sister, Lyn. It seems Lyn and Bonnie have a lot in common: they’re both too young to be Trainers, but they love taking care of their older siblings’ Pokémon. They also carry identical bags, which leads to a mix-up: as they’re leaving the Pokémon Center, Lyn accidentally picks up Bonnie’s bag, and Bonnie takes Lyn’s. The girls don’t realize their mistake until they discover the wrong Pokémon inside: Lyn has ended up with Dedenne, and Bonnie is surprised to see a Pichu peering up at her! Lyn immediately runs off to try to find Pichu, leaving Lena trying to find her!
As soon as they figure out what’s happened, Ash, Serena, Clemont, and Bonnie return to the Pokémon Center to ask around. Lyn hasn’t come back, but Nurse Joy remembers a girl with a bag that looks like Bonnie’s, wearing a red ribbon in her hair. Our heroes set off in search of the little girl, and a passerby directs them to the park where she usually plays, but they have no luck. Finally, Clemont decides that the situation calls for one of his inventions! He remembers how Pikachu and Dedenne communicated with electricity the first time they met, and shows off a device that will broadcast Pikachu’s electricity over a wide area in hopes that Dedenne will sense it and come find them.
At first, it seems to be working—but as usual, it explodes when Clemont tries to give it more power. The commotion draws the attention of Lena, who has also come to the park looking for Lyn. And on the other side of the park, Dedenne has picked up on the electricity and runs off in search of the source, with a frantic Lyn chasing after it! The two of them run into a wooded area—and right into an angry Beedrill. Dedenne bravely fights it off, but then the whole swarm descends...until an unexpected Thunderbolt scatters them! Pikachu, Ash, and the others have found the wayward Dedenne and Lyn just in time. The girls trade bags again, reuniting Dedenne with Bonnie and Pichu with Lyn, and everyone settles in to have lunch together before our heroes continue their journey!