Ash and co. are in Slateport City. May is excited to do some shopping. Max wants to check out the cool museum. Ash asks Pikachu if it wants to check out the museum. Brock states that he also needs to do some shopping. Ash and Max decide to check out the museum, while May and Brock does their shopping.

When Ash and Max arrive at the museum, the find out that the museum is closed. Ash finds it weird since the museum is suppose to be open everyday. Max doesn't want to give up yet. Max tries to climb the wall in order to get inside. A boy walks up to Max. Max falls onto the ground. The boy asks why Max was climbing the wall. The boy accuses Max of being a thief. Ash walks up to Max and asks what's wrong. The boy assumes Ash is a thief too. He wants to teach them a lesson. The boy sends out a Spheal. Ash looks up Spheal in his Pokédex. The boy tells Spheal to use attacks, but Spheal fails to use everyone of them except for Blizzard. Pikachu knocks Spheal out with Thunderbolt. The boy wonders how Pikachu was able to beat Spheal so fast. Max explains to the boy that Spheal is at a huge disadvantage against electric types.

A man walks out. He sees the boy. The man refers to the boy as Marius. The man is Captain Stern. The boy reports to Captain Stern that Ash and Max are thieves. Max tells Marius that he just wanted to visit the museum. The boy asks Max why he was climbing the wall. Max tells him that he just wanted to take a peak inside the museum since the front door was locked. Captain Stern is in charge of the museum. He tells Ash and Max that there was a problem earlier, so the museum had to be closed down. However, he invites Ash and Max to take a look around in the museum.

Meanwhile, Team Rocket has been spying on Ash and Max. James suggests they steal Pikachu and everything in the museum. Jessie and Meowth like James's idea. Captain Stern gives Ash and Max a tour of the museum. He leads them to a room where model Pokémon are displayed. They see a Wailord and many other kinds of Pokémon. One of Marius's favorite Pokémon is Goldeen. He wants one because he thinks it will evolve into Gyarados. Ash and Max laugh because only Magikarp evolve into Gyarados. Marius doesn't care about the amount of information he knows. He wants to travel in the submarine that Captain Stern is building.

Captain Stern picks up his briefcase. He shows Ash and Max a rock. The rock almost looks like it has been burnt. Captain Stern says that he received it today. It was found underwater. Ash and Max wonder how a rock could have heat from under the water. A Pokémon could've caused the heat. Suddenly, they hear a group of snow cone salesmen from outside. Captain Stern suggests they all get a snow cone. He wants to work on analyzing the rock. Ash, Max, and Marius walk outside. The snow cone salesmen are Team Rocket. They give each of them a snow cone. Ash, Max, and Marius get a brain freeze when they are finished eating their snow cone. Team Rocket then picks up Pikachu. Since Ash, Max, and Marius have a brain freeze, they can't move. A cage drops down on them. Then James puts Pikachu in a cage. They say their motto.

A Team Magma member has gone in the museum. He pulls a lever causing a blackout. Three other Team Magma members walk towards Captain Stern's rock sample. They steal the sample. Captain Stern walks in and see Team Magma. He wants to know what they plan to do with his rock. Team Magma doesn't tell Captain Stern. One member sends out Mightyena. Mightyena uses Shadow Ball filling the room with smoke. When the smoke clears, Team Magma is gone.

Ash tells Pikachu to use Thunderbolt. The attack doesn't break the cage. Team Rocket's next part of their plan is to rob the museum. Before they can head to the museum, they see Team Magma running off with their treasure. Ash and Max recognize Team Magma immediately. They have to do something before Team Magma escapes. Marius sends out Spheal. He orders Spheal to use Body Slam. All Spheal does is clap. Ash sends out Corphish. Corphish uses Crabhammer to break the cage.

Team Rocket sends out Seviper and Cacnea to block Team Magma's way. Team Rocket orders Team Magma to give them the rock. Seviper attacks with Poison Tail. Mightyena counters with Tackle. Then Cacnea uses Pin Missile. Mightyena dodges the attack by using Double Team. Seviper then uses Wrap, but Mightyena counters by using Iron Tail. Team Rocket blasts off into the sky.

Ash and co. have managed to escape from their cages. Ash demands Team Magma to give them back the rock. Captain Stern runs up to them. He wants to battle Team Magma. Captain Stern sends out Sealeo. Sealeo uses Aurora Beam. The beam hits Mightyena. Mightyena falls back and knocks into the member that is carrying the briefcase. The member drops the briefcase, and Marius catches it. Then the other two members of Team Magma send out their Mightyena.

Brock and May are now done with their shopping. They decide to head back to the museum. The Team Magma leader wants the stone back. Captain Stern refuses to give the stone back. Ash sends out Corphish to battle. Captain Stern tells Max and Marius to find Officer Jenny when he tells them to. The three Mightyena fire their Hyper Beam attacks. Corphish uses Bubblebeam, Pikachu uses Thunderbolt, and Sealeo uses Aurora Beam. All the attacks collide into each other. Captain Stern orders Max and Marius to leave now. Marius leads Max to the edge of a cliff. He tells Max that they will jump into the ocean. Mightyena prepares for a Shadow Ball attack. It fires the attack at Max and Marius. They have no choice. Max, Marius, and Spheal jump into the ocean. The Shadow Ball misses them.

Spheal swims super fast to land. When they arrive at land, they meet up with Brock and May. Captain Stern and Ash continue to face Team Magma. Captain Stern tells Ash to take the briefcase and run while he distracts Team Magma. Ash agrees to the plan. Sealeo attacks Team Magma with Blizzard. This gives Ash time to run. The leader sees Ash trying to escape. Mightyena fires a Shadow Ball to block Ash's way. The briefcase drops out of Ash's hands. It opens up and the rock falls on the ground. The rock has split into two pieces. Mightyena picks up the bigger piece and hands it over to the leader. Then Team Magma's plane arrives. Mightyena uses one last Shadow Ball, and then Team Magma escapes.

The police arrive and begin to investigate. Ash apologizes to Captain Stern for letting Team Magma get away with the rock. Captain Stern holds out the small piece of rock to Ash. He still has enough to begin his research. Ash and co. wonder what Team Magma plans on doing with the rock. Whatever it is, Ash knows it's nothing good. Marius asks Ash where he is headed next. Ash tells Marius that him and his friends are going to Mauville City. The next time Marius meets Ash, he wants to have a battle. Ash agrees to the battle, although Marius has a lot of praticing to do. Then Ash and co. wave goodbye to Marius and Captain Stern and head down towards Mauville City.

English Official Summary

Fresh out of the contest, our heroes are exploring the bustling city of Slateport. Ash and Max want to check out the Sea Museum but discover that it is not only closed, but sort of being guarded by a boy named Marius and his Spheal. After a failed attempt at attacking Ash's Pikachu, the boy recalls his Spheal. Captain Stern, the curator of the museum, appears and offers Ash,Max, and Marius a tour of the museum. Team Rocket is, of course, observing all this and devising a way to steal Pikachu. Captain Stern then shows them his latest discovery, a volcanic rock from the bottom of the ocean. He tells them about how it was believed in some cultures that a giant Pokémon caused volcanic eruptions. Team Rockets calls from outside, selling ice cream, and the boys decide to go out and get some. During this time, Team Magma members infiltrate the museum and steal the volcanic rock. At this point, Team Rocket captures Pikachu. When they see Team Magma running away, though, they divert their attention to attacking them. Team Magma sends them blasting off again. A battle breaks out between the Captain Stern, Ash, and Team Magma. Marius and Max escape by using the Marius' Spheal and they meet up with Brock and May. Ash tries to escape the battle with the rock, but it falls and the stone breaks in two. One of the Mightyena grabs half the stone and Team Magma retreats with their prize.

French Official Summary

Après avoir enfin terminé son Concours Pokémon, Flora propose un jour de repos à Poivressel avant de reprendre la route. Tandis qu’elle fait quelques courses avec Pierre dans un marché renommé, Sacha et Max visitent le Musée Océanographique. Mais, ce qui aurait dû être un jour de vacances, se transforme en une succession de combats contre la Team Rocket et la Team Magma, qui sèment la pagaille dans le musée, en cherchant une pierre rare découverte au fond de l’océan.

German Official Summary

Direkt nach dem Wettbewerb erkunden unsere Helden Graphitport City. Ash und Max möchten ins Meeresmuseum, aber es hat geschlossen.

Italian Official Summary

Al termine della Gara, i nostri eroi decidono di esplorare l'animata città di Porto Selcepoli. Ash e Max vorrebbero visitare il museo del mare ma purtroppo scoprono che è chiuso.

Portuguese Official Summary

Um dia de descanso na Cidade de Slateport acaba num confronto entre a Equipe Rocket e a Equipe Magma!

Spanish Latin America Official Summary

¡Un día de relajación en Ciudad Slateport se convierte en una confrontación entre el Equipo Rocket y el Equipo Magma!

Spanish Official Summary

Tras terminar por fin su concurso Pokémon, Aura propone un día de ocio en Ciudad Portual antes de seguir su camino. Mientras ella y Brock van de compras por la zona comercial más famosa de la ciudad, Ash y Max van al Museo del Mar. Sin embargo, lo que tenía que haber sido un día de ocio acaba convirtiéndose en un combate tras otro, pues el Team Rocket y el Equipo Magma llegan a ese mismo museo en busca de una extraña roca descubierta en el lecho oceánico.

English Great Britian Official Summary

Fresh out of the contest, our heroes are exploring the bustling city of Slateport. Ash and Max want to check out the Sea Museum but discover that it is not only closed, but sort of being guarded by a boy named Marius and his Spheal. After a failed attempt at attacking Ash's Pikachu, the boy recalls his Spheal. Captain Stern, the curator of the museum, appears and offers Ash,Max, and Marius a tour of the museum. Team Rocket is, of course, observing all this and devising a way to steal Pikachu. Captain Stern then shows them his latest discovery, a volcanic rock from the bottom of the ocean. He tells them about how it was believed in some cultures that a giant Pokémon caused volcanic eruptions. Team Rockets calls from outside, selling ice cream, and the boys decide to go out and get some. During this time, Team Magma members infiltrate the museum and steal the volcanic rock. At this point, Team Rocket captures Pikachu. When they see Team Magma running away, though, they divert their attention to attacking them. Team Magma sends them blasting off again. A battle breaks out between the Captain Stern, Ash, and Team Magma. Marius and Max escape by using the Marius' Spheal and they meet up with Brock and May. Ash tries to escape the battle with the rock, but it falls and the stone breaks in two. One of the Mightyena grabs half the stone and Team Magma retreats with their prize.

Russian Official Summary

Потратив много сил на последнем состязании покемонов, Мэй решает устроить день отдыха и предлагает передохнуть в Слейпорт Сити. Пока она ходит по магазинам вместе с Броком, Эш и Макс решают посетить Музей океана. Когда оказывается, что музей закрыт, хотя должен быть открыт ежедневно, Макс решает перебраться через стену, и его принимают за вора. Эш и Макс объясняют ситуацию Капитану Штерну, куратору музея, который позволяет им зайти. Он только что получил новый каменный образец, который привлёк внимание Команды Магма и Команды Р. Эшу и капитану Штерну удаётся одолеть их, но во время битвы камень ломается. Капитан Штерн не понимает, что нужно Команде Магма, но решает продолжить исследования оставшегося кусочка камня.

Dutch Official Summary

Een dagje ontspanning in Slateport stad verandert in een confrontatie tussen Team Rocket en Team Magma!

Danish Official Summary

En afslappet dag i Slateport City ender med et sammenstød mellem Team Rocket og Team Magma!

Swedish Official Summary

En avslappnad dag i Slateport City förvandlas till en sammandrabbning mellan Team Rocket och Team Magma!