On the way to the Grand Festival at Lake Valor, Ash and friends arrive in a small town and run into a young boy who left his Magby at what was apparently a fake Daycare Center. As a result, it was stolen, so Ash and friends decide to help. After they begin their search for Magby, they encounter a woman who introduces herself as Bertha, and who also seems to know how to find Magby. While Ash and Dawn don't see it themselves, Brock realizes who Bertha is. What is Bertha's secret?

Continuing on to the Grand Festival, Ash and friends find a girl named Marley in a river and swiftly bound for a waterfall. Brock rescues her, and they find out that a legendary Shaymin is with her, injured by a group of thugs who want to steal it. Team Rocket, who are the ones responsible, set out in an attempt to nab Shaymin once more. Ash and friends, knowing the danger, join Marley in helping to keep Shaymin safe while returning it to its friends.

With Ash's Sunyshore Gym match delayed, Ash and friends head towards Lake Valor for the Grand Festival. They meet up with Dawn's mother Johanna who asks them to help out at a school. They help out, but things get hectic, especially when a kid takes a "liking" to Piplup. Dawn decides to use this time at the school to perfect some combos for the Grand Festival, while Jessie sets her sights on her fourth ribbon.

At last, the time has come; Ash is finally going to battle Volkner, Leader of the Sunyshore Gym. If he wins this, then the Beacon Badge is his and it'll be on to the Sinnoh League. The battle gets underway, but just as they're getting warmed up, a city-wide power-outage occurs, putting their match on hold. The group heads over to the Sunyshore Tower, the city's power source, in order to see what the problem is, and they see it right away... or rather, they don't see it: the tower has completely disappeared! Will Ash and friends, as well as Volkner and Flint, be able to trace down the lost tower and bring it back, or will Sunyshore City remain in a state of electrical darkness until it receives another source of power?

Ash and friends have finally arrived in Sunyshore City, where Ash will challenge the Gym Leader in an attempt to win his eighth and final badge. Upon arriving at the gym, however, Ash is outraged to discover that a giant pile of Beacon Badges are lying right outside the front door, waiting for anyone who happens to walk by to simply take one. When he tries to enter the gym to get to the bottom of this, however, he's caught by the gym's high-tech security. Just then, an Infernape appears to save him, and it belongs to none other than Flint of the Elite Four, an old friend of the Gym Leader, Volkner. It is revealed that Volkner has lost his battling spirit, thus why the badges were left for anyone to take them. Flint, however, has a plan to snap him out of it and get him excited for Pokemon Battles again. Can Flint, with the help of Ash and friends, rekindle Volkner's battling spirit?

Piplup is getting sick and tired of being constantly hit by Gible's failed Draco Meteor attacks. Fed up, Piplup runs away, and heads towards Professor Rowan's lab. Will Dawn be able to find her beloved pokemon?