It's the day after Pastoria City's Croagunk Festival—and while Team Rocket may have time to enjoy a leisurely marsh mud bath, Ash and his Pokémon must train for their Pastoria Gym battle. Buizel is so focused on victory that it loses its temper at Pikachu, then takes it out on Turtwig when the Grass-type Pokémon tries to play peacemaker. It's not a promising start to the morning but the Pastoria Gym Leader, Crasher Wake, is intrigued by Buizel's spirit; he shows Buizel his own Floatzel, capturing Buizel's interest.

Everyone moves to the Gym, where Crasher Wake welcomes Ash to the water-based battlefield for a three-on-three battle. For their first face-off, Crasher Wake chooses Gyarados and Ash chooses Pikachu. Pikachu's initial Electric attack doesn't faze Gyarados, but a mid-air Volt Tackle puts Gyarados down for the count. Next up is Crasher Wake's Quagsire, so Ash switches in Turtwig. Turtwig darts around the pool to throw off Quagsire, but Quagsire can still track Turtwig's every movement—Ash hastily withdraws Turtwig and sends out Buizel in its place.

Buizel is still annoyed with Pikachu, forcing Ash to call its attention back to the fight. Buizel turns Quagsire's Ice Beam attack into a frozen Aqua Jet combo, knocking out Quagsire, and Buizel's real opponent enters the ring: Floatzel! Floatzel takes everything Buizel can dish out and comes back for more, using its flotation collar to help absorb incoming attacks. Then, confused by its own attack, Buizel is forced to take a break while Pikachu subs in, but Floatzel soon has Pikachu on the ropes. Buizel recovers and takes over the fight, giving Pikachu a high-five, and knocks out Floatzel with an aerial Water Pulse. With that, Ash's team scores a clear victory earning him a brand-new Fen Badge!