The episode starts off with May talking about her little 'expedition'. She continues on about the amazing ship, which 'is a city crammed into an ocean liner'. Max says that the ship is cool. May brags that if it weren't for her, they wouldn't even been on that ship. Ash and co. talk about her soon to come victory in the Grand Festival.

The narrator speaks about the route to the Grand Festival held at Slateport City. May is looking at a map in looking for a room. Once the gang find where they are, they are at mini-Pokémon Center. Ash and co. are amazed that the ship has it's own Pokémon Center. Brock then starts to flirt with Nurse Joy. Max (once again) grabs him by the ear, and drags him back. May asks Joy if she can take care of her Pokémon. Joy asks if her Pokémon need rest or excercise. Joy explains about the playroom designed for Pokémon. May says that her Pokémon can rest first then play. She sends out her Pokémon. Max asks Munchlax if it's hungry.

After leaving the center, the gang are walking along the halls of the ship. May says that it's not everyday you are on a luxury liner. She wants to see everything. The gang stops in surprise when they see Officer Jenny and her Growlithe patrolling by. Brock starts to flirt with Jenny. He offers her a bouquet of roses. Max pulls Brock by the ear (again). Ash asks what she is doing on aboard. Jenny answers that a crime hasn't been committed yet. Ash replies then why is she on the ship. She answers that she is hunting the phantom thief Brody. Max is remembering that he must’ve heard that name before. Jenny says that he is a Team Magma member with many faces. Than the gang snaps as they all know who Jenny is talking about. Brock goes on saying that he was the guy from the Weather Institute. He stole lots of data on Ancient Pokémon, and disguised himself as a woman named Milly. May wonders why he would go and change his name. Max says that he probably decided to quit Team Magma.

As they are all speaking about Brody, Team Rocket overhears them in their disguises as custodians. They plan out they are going to rob Pikachu. Back to the scene with Officer Jenny and the gang, she is explaining to Ash & co. that Team Magma and Aqua have disbanded, the two teams decided it was impossible to control Groudon or Kyogre. Yet, Brody is a theif who steals jewels and artwork she adds on. She also clears up that the Phantom Thief is on the ship attempting to steal something. She asks Ash & co. to report any suspicious behavior to her right away. After hearing that, Brock then again decides to flirt with Officer Jenny. As Max is trying to restrain Brock, Team Rocket go off.

James says that they are going to meet Brody, and all that, but Jessie says that Aqua and Magma have 'dissolved' and Team Rocket is still in the scene. She continues on that they can take the credit for disbanding them. James is starts saying that once the boss hears about this, he'll say "I'll let Team Rocket run the whole Hoenn region".

May is leading the gang and Ash asks where they are even going. May answers that there is something that she wants to see. They are arriving at their destination. They see the Ribbon Cup. May says that is the cup given to the winner of the Grand Festival. She imagines herself winning it. Suddenly, May's Munchlax is running around and enters where Ash & co. are. As a security guard is chasing it, Max and Brock say that it is out looking for food. It jumps on a chair and eats the food on the table. May lectures Munchlax about not eating other people's food. It's running towards the Ribbon Cup. It hits the platform where the Cup was, and Munchlax falls on it's backside. Max then feeds Munchlax some of May's pink surprise. Ash says oh no in horror and shock when they see a handle of the cup broken off.

Contesta is staring at the broken Ribbon Cup. Max and May are trying to explain everything. May says she didn't mean it. Contesta is saying that no coordinator would ever break the Ribbon Cup on purpose. But then he says that the Cup shouldn't have broken that easily. Once finish looking at it, he notices it that it is a fake. He says that the real Ribbon Cup has a seal from the Contest Committee. Ash & co. are asking each other where the real one is. Then from the bottom of the cup, a card fell out which was purple and a reddish type mark on it.

When Officier Jenny is looking at the card, she says that Brody has stolen the Ribbon Cup. She asks to herself how he could of stolen it with security guards everywhere. Overhearing them in the vents, Team Rocket are skying on Ash & co. They are complaining that Brody is getting away with it. Jessie says that they will steal it from him. Than the back up through the vents. Contesta goes on that they may have to cancel the Grand Festival because without a Ribbon Cup, no one will win anything. May says that she and lots of other coordinators worked hard to make their way to the Grand Festival. Contesta says that's the only Cup they have for the Slateport City Contest. They would have to make another one which they don't have the time to do. Jenny says not lose hope as Brody is still on board and their at sea so there is no way to escape. The gang says that they will help. Brock then starts to flirt with Jenny.

The gang start searching for Brody, the first place they go is to the security guards. The guards say that if they were any suspicious behavior, they would have caught it. Jenny then asks how they handled their lunch breaks. One of the security guards say that one of them came back early because they forgot something. But the other guard explains that he didn't come back early. The gang puts the pieces together and it was Brody. Max says that Brody must of changed disguises. They can't find Brody because he could be anyone. Jenny says that they are going to have to have to coax him out with a Pokéball she is spray painting gold. The gang are complimenting Jenny on a nice Pokéball job.

Then the gang are just going around and spreading rumors about the 'Golden Pokéball'. After everybody is done spreading rumors, they are in the room where the Pokéball is, and they say that Brody must of heard one of them. They hear somebody coming towards that room. Ash & co. are going to hide. We then see Team Rocket in their disguise. Team Rocket says that no one is in the room, so they are going to steal the Pokéball.

Ash & co. catch them but they are saying that there is two Brody's. Then Team Rocket reveals themselves. James says that they are the Team Rocket who put the end to Team Aqua and Magma. Ash tells Pikachu to use his Thunderbolt. They blast off and land in the ocean.

The captain then rushes in and reports to Jenny that all the Pokémon are being stolen in the Pokémon Center. The gang immediately rush to the Pokémon Center, the captain pops out and tells. They all discuss why he showed after he was in the room, and what’s happening at the Pokémon Center. Everything is fine there and that wasn't the real captain back where the Golden Pokéball was. They rush back to the room where the Pokéball was, and they catch Brody. Brody then reveals himself after he says that they were pretty quick. Ash says that he won't get away with it.

Jenny says that Brody is under arrest. But Brody sends out Golbat to use its Haze attack. After the haze was gone, Brody disappeared. The gang are disappointed that they won't be able to catch and fool Brody the same way again. But Jenny has no worries because she says that she hid a transmitter in the Pokéball.

The gang and Jenny are looking at the transmitter map, and Jenny says that Brody is up ahead. They arrive at the table which on the map says that Brody is right in front of them, and the lady at the table says is something wrong but Brody runs off after Jenny said that she was Brody.

They are running the halls, Brody makes a turn, and changes disguises leaving the lady disguise behind. Jenny says to the gang to follow her. They arrive in the cooking kitchen where Brody is 'supposed' to be in their, but is hard to locate him with lots of cooks around.

Anyone of the cooks could be Brody. They then see a cook asking the Master Chef if what he's holding a good meal for dinner. The Master Chef says that it is delicious. The Master Chef then excuses himself, and walks off. Then from the door where that chef was standing, another Master Chef walks in. Jenny says that the other Master Chef was Brody. They are going down the stairs, but under that staircase, was the Pokéball. Ash is about to pick up the ball with Jenny thinking taht Brody knows the scheme that Ash & co. are planning. When Ash picks up the Pokéball, it opens up with party streamers and Brody's 'calling card'. May says that he definitely is on to them.

Max then says that Brody is probably on deck because last at the Weather Institute when he escaped, he used a jetpack. Brock says that he is probably going to use that same tactic again. Jenny says that they have to the deck.

Once on deck, Ash says that no one is on the deck. Max then sees Officer Jenny coming up to the deck. But then on the other entrance/exit on the deck on the other side, another Jenny walks up to the deck. The two Jennys are arguing over who's the real one and who's Brody. Ash, May and max are having no clue who's the real Jenny. Brock points to the left Jenny yelling that she's the fake. Jenny is surprised that Brock could say that. Brock walks up to her and talks normally. Then when going to the other Jenny at the right, he has heart-felt eyes, and is flirting with her. Max agrees with Brock, than the real Jenny is walking towards the fake one, to come with her. Brody chuckles, takes off the Jenny disguise and is holding the Ribbon Cup. Brody compliments Jenny of how good she is. Brody continues speaking and saying that the Ribbon Cup isn't really valuable. He then throws the cup to Jenny. As Jenny is about to catch it, the machine grabs the Ribbon Cup.

Team Rocket sings their motto, but saying also that they put an end to Magma and Aqua. Brody is about to leave saying that this is all nonsense. Jenny says not to move, but Brody flies off with his jetpack. Team Rocket and Ash & co. engage in another Pokémon Battle. Jenny sends out Growlithe, Jessie sends out Seviper. Growlithe uses Flamethrower, while Jessie's Seviper dogeing it and using Poison Tail. Growlithe is hit. Pikachu joins in, and orders it to use Thunderbolt. James sends out Cacnea. Growlithe uses Flamethrower once more and Pikachu using Thunderbolt again. Seviper and Cacnea are hit. Pikachu uses Thunder to blast Team Rocket off. As they are blasting off, Jessie and Meowth are discussing that they wanted credits for defeating Team Aqua and Magma.

--Commercial--

The Ribbon Cup is back in its display case, and Contesta is happy about that, and thanks Ash & co. for all their help. Jenny says that Pokémon Co-ordinators will have a chance competing for the Ribbon Cup at the Grand Festival. At sunset, they are nearly at Slateport City; May says that she will win the Ribbon Cup. The episode is ending, and the narrator is recapping the episode in a few words.

English Official Summary

May is traveling to Slateport City in style: onboard a giant cruise ship that has the Grand Festival's prize Ribbon Cup on display! Officer Jenny reveals that even though Team Magma and Team Aqua have disbanded, a former Team Magma member—Brodie the Phantom Thief—is onboard and intent on stealing valuables. When May goes to see the Ribbon Cup, Munchlax bumps the display case, breaking the Cup and revealing that it's a fake. And without the Cup, the Grand Festival will be called off! Brodie must have stolen it, so a "Golden Poké Ball" is put on display as a lure. Disguised as the Captain, Brodie distracts May and her friends and steals the Poké Ball, but Officer Jenny had a tracking device installed in it and they set off in hot pursuit. They chase Brodie through the ship, finally cornering him on deck. Brodie has now disguised himself as Officer Jenny and the only way to distinguish between the two is with Brock's keen eye for lovely ladies. Once his ruse is rumbled, he escapes and Team Rocket tries for the Ribbon Cup instead. But Officer Jenny and Ash are up to the job, and Team Rocket's plans are thwarted.

French Official Summary

L'agent Jenny apprend à nos héros que, malgré la dissolution de la Team Magma et de la Team Aqua, un ancien membre de la Team Magma (Brodie, le voleur fantôme) est à bord du navire pour y dérober des objets précieux.

German Official Summary

Durch Officer Rocky erfahren unsere Helden, dass Team Magma und Team Aqua sich zwar aufgelöst haben, aber ein ehemaliges Mitglied von Team Magma – Brody der Phantomdieb – an Bord ist, um Wertgegenstände zu stehlen.

Italian Official Summary

L'agente Jenny rivela che anche se i Team Magma e Idro si sono sciolti, Brody, un ex membro del Team Magma, detto il ladro fantasma, è sempre pronto a rubare oggetti di valore.

Portuguese Official Summary

A bordo de um cruzeiro de luxo rumo à Cidade de Slateport e o Grande Festival, nossos heróis precisam ajudar a Oficial Jenny a capturar um mestre ladrão!

Finnish Official Summary

Slateport Cityyn ja Suurjuhlille matkalla olevan luksusristelijän kyydissä olevien sankareittemme on autettava konstaapeli Jennyä nappamaan mestarivaras!

Spanish Latin America Official Summary

A bordo de un lujoso crucero con destino a Ciudad Slateport y al Gran Festival, nuestros héroes deben ayudar a la Oficial Jenny a atrapar al ladrón maestro.

Spanish Official Summary

La Agente Mara revela que, aunque el Equipo Magma y el Equipo Aqua hayan desaparecido, un antiguo miembro del Equipo Magma, Brodie el Ladrón Fantasma, está a bordo y trata de robar objetos valiosos.

English Great Britian Official Summary

May is traveling to Slateport City in style: onboard a giant cruise ship that has the Grand Festival's prize Ribbon Cup on display! Officer Jenny reveals that even though Team Magma and Team Aqua have disbanded, a former Team Magma member—Brodie the Phantom Thief—is onboard and intent on stealing valuables. When May goes to see the Ribbon Cup, Munchlax bumps the display case, breaking the Cup and revealing that it's a fake. And without the Cup, the Grand Festival will be called off! Brodie must have stolen it, so a "Golden Poké Ball" is put on display as a lure. Disguised as the Captain, Brodie distracts May and her friends and steals the Poké Ball, but Officer Jenny had a tracking device installed in it and they set off in hot pursuit. They chase Brodie through the ship, finally cornering him on deck. Brodie has now disguised himself as Officer Jenny and the only way to distinguish between the two is with Brock's keen eye for lovely ladies. Once his ruse is rumbled, he escapes and Team Rocket tries for the Ribbon Cup instead. But Officer Jenny and Ash are up to the job, and Team Rocket's plans are thwarted.

Russian Official Summary

Шикарный лайнер, идущий в Слейпорт Сити, где состоится Большой фестиваль, еще не отошёл от причала, а Эш и его друзья узнают, что на борту находится знаменитый вор. До начала фестиваля остаются считанные часы, а главный приз фестиваля - Кубок лент - пропадает. Зная, к какой катастрофе может привести пропажа кубка, наши герои вместе с Полицейской Дженни разрабатывают операцию по поимке вора, который является мастером маскировки и быстро меняет обличия.

Dutch Official Summary

Aan boord van een luxe cruisschip op weg naar Slateport City en het Grand Festival, moeten onze helden Agent Jenny helpen met het vangen van een meester dief!

Norwegian Official Summary

Heltene våre må hjelpe Officer Jenny med å fange en mestertyv om bord på et luksusskip på vei mot Slateport City og Den store festivalen!

Swedish Official Summary

Ombord på en lyxkryssare på väg till Slateport City, där Grand Festival ska hållas, måste våra hjältar hjälpa konstapel Jenny att fånga en mästertjuv!

Danish Official Summary

Om bord på en luksusliner med kurs mod Slateport City og Den Store Festival hjælper vore helte Betjent Jenny med at fange en mestertyv!