Dawn and Piplup are hard at work on a new BubbleBeam combination, but Piplup works so hard that it passes out from exhaustion! Dawn and the gang rush Piplup to a Pokémon Center for some much-needed rest. Team Rocket is also exhausted, but not from hard work; after a well-fed week at the Pokémon Summer Academy and a stop at an all-you-can-eat restaurant, Team Rocket realizes they've put on weight. Now they're so out of shape, they're more likely to give up their seats to an elderly couple than pull off a criminal caper! Horrified, Team Rocket resolves to get back to basics and begins an exercise program.
Over at the Pokémon Center, Dawn apologies to Piplup and gets some advice from Professor Oak. While Dawn talks to other Trainers to pick up training tips, her friends perform chores to help Nurse Joy. Meanwhile, Team Rocket sneaks into the Pokémon Center and begins stealing Poké Balls from the repository. Piplup wakes up when it hears the noise; it sounds the alarm as soon as it sees Team Rocket, bringing Ash and his friends running to the scene of the crime.
When our heroes confront Team Rocket outside the Pokémon Center, Team Rocket proudly unveils their latest giant mecha. It's captured all the Poké Balls and it's too powerful to approach, but Piplup uses BubbleBeam to cloud up its windshield. Then Pikachu and Happiny recover the stolen Poké Balls, and Pikachu's Thunderbolt sends Team Rocket sailing away into the night sky—Team Rocket's back to basics plan got them a basic robot with no shielding against electricity! The next day, since Piplup is healthy again, Dawn and her friends set off for Celestic Town and the next Pokémon Contest.