The keepers of Shift Station, Kokoro and her granddaughter Chimney, point the Straw Hats in the direction of the metropolitan Water Seven. The nearby city is regarded as the best place to find a decent shipwright for the Going Merry.

The Straw Hats cash in their Skypiean gold and meet up with Iceburg, the celebrity mayor of Water Seven, to see about an appraisal for their ship's repairs. While the foreman Kaku checks the Merry, dubious people eye the pirates' money.

Kalifa shows Luffy and co. around Dock One and tells them about Iceburg and Galley-La Company. During the tour, Kaku returns with some bad news, and a long-nosed Straw Hat goes missing… along with the money he was watching!

The Straw Hats raid the Franky House, but they soon find that their real target, Franky, is long gone with the stolen money. When the battered Usopp awakens, nothing can prepare him to hear what Luffy has decided about the Merry.

Usopp is unwilling to say farewell to the Going Merry… not without a fight, that is! He challenges his former captain to a duel between men, so Luffy honors the pride of his former crewmate and faces him in battle.

Iceburg has been shot! When Luffy and Nami decide to go check on him, the fire-breathing, half-mechanical Franky challenges the Straw Hats’ captain. Before their fight gets too heated, Galley-La swoops in with an unexpected accusation!

Things are hectic enough with Franky going after Luffy, but now the Straw Hats are being framed for a crime seemingly committed by Nico Robin. As if to put the proverbial icing on the cake, the annual storm Aqua Laguna is on its way toward …

Nico Robin appears to be working alongside a World Government shadow organization called CP9. When the Straw Hats learn about Robin's current affiliation, Luffy decides that in order to know the full truth, they must catch Robin and make he…

Robin and her tall, mysterious, masked companion arrive at Iceburg's room, and she learns that he possesses blueprints to the ancient weapon Pluton, spoken of in the poneglyphs. Then, shockingly, the members of CP9 unmask themselves.

Luffy's group finally catches up to Robin, but they are greeted by disappointment—Robin opts to stay with CP9 and leave the Straw Hats. As Robin turns away from Luffy, the members of CP9 confronts the pirates.

As Usopp works to repair the Going Merry, he contends with Franky's insistence on dismantling it. During this time, Usopp reflects on who it was that conducted the ship's repairs while in Skypiea, and Franky confirms his suspicions.

In the past, Franky—a.k.a. Cutty Flam—was part of the legendary Tom's Workers, and he and Iceburg helped create the sea train. Spandam, a member of CP5, was determined to get Tom's blueprints for Pluton by any means necessary.

The old fishman Tom was framed by CP5 for the crime of attacking the Marines with Franky's battleships. As the World Government hauled Tom off to Enies Lobby, Franky received a lasting reminder to take pride in the ships he builds.

CP9 hauls away Franky and Usopp, but not before giving a coldhearted farewell to the Merry. At Galley-La’s HQ, Nami learns from Iceburg the truth behind Robin's betrayal and the difficult choice she had to make to save the lives of the Stra…

While the members of Galley-La help Chopper search for Luffy and Zoro, Nami rushes to the departing sea train to keep Robin from sacrificing her freedom. At the station, a man finds Nami and hands her a letter from Sanji.

Sanji coolly fights his way through the sea train and locates Usopp and Franky. Back in Water Seven, Kokoro sees how determined Luffy is to save Robin, so she and Iceburg lend the Straw Hat crew an unexpected helping hand.

Rocketman blasts out of Water Seven and connects with the sea tracks, and old foes become allies for the coming struggle. Aqua Laguna swells, and it's up to Luffy and Zoro to combine their might and create safe passage for all aboard.

Sogeking appears in grand fashion! Wanze threatens Sanji's group with his ramen kenpo, so the Straw Hat cook urges the others ahead. Franky takes on CP9's newest recruit “Sea Weasel” Nero, and Sogeking moves forward to meet up with Robin.

In his battle against Wanze and his strange Ramen Kenpo, Sanji makes an exception to his rule of never using his hands. Meanwhile, Franky and Nero are baffled by each other’s abilities, and back on Rocketman, Zoro clashes with “Ship-Slasher…

Sanji and Franky conclude their fights and enter the train car where CP9’s agents lie in wait. When Sogeking sees the danger of the situation, it falls to him to formulate a plan for escape. However, CP9 is far from being thwarted!