Ash seeks the Cascade badge in Cerulean City—but for some reason, Misty doesn't want to join them. When Ash and Brock show up, the city is buzzing about a break-in that just took place—and are initially accused of the crime! (We see Team Rocket commit the robbery, but no one else knows about their involvement yet.)

Ash and Pikachu arrive at the Cerulean City gym, which resembles an aquarium with an Olympic-sized swimming pool. They see a water show performed by the Sensational Cerulean City Synchronized Swimming Sisters. Later on, Ash learns that the sisters are actually the Gym Leaders. He challenges them, but they don't feel like battling and instead offer him the Cascade Badge without a fight.

It looks like Ash will have his Cascade Badge without breaking a sweat...but then a fourth Gym Leader step up! Who is this mysterious Gym Leader? What does Team Rocket plan to do with the stuff they stole? And where's Misty?