Pluton is one of the three Ancient Weapons, alongside Poseidon and Uranus. Pluton is a huge and highly advanced warship capable of mass destruction, constructed long ago in the city of Water 7 in the Grand Line. The battleship is said to be capable of destroying whole islands. Pluton was first mentioned by Crocodile when he questioned Nefertari Cobra of its whereabouts.
It is supposed to be a large warship of some kind. Both Franky and Iceburg were shocked when seeing the blueprints, wondering how a ship like Pluton could be built in the first place. Not much else is known about it.
Abilities and Powers
Its power was as dangerous as other weapons like Poseidon, who herself had the power to sink all the world's islands into the ocean, although exact details of its capabilities remain unknown. Whoever controlled the weapon had the potential to conquer the world in the process and in the wrong hands would be dangerous. Likewise, Pluton also had the ability to do as much damage to the world. Furthermore, because the blueprints remained in existence even after the ship was built, whoever possessed the blueprints to the vessel would have the potential to build a fleet of vessels with the same destructive abilities as each other.
The blueprints had been preserved as a means of bringing Pluton back into existence should the world ever need it to fight the weapons, including the original Pluton itself. At this point, however, the blueprints which were used to create it are now destroyed while Pluton itself is still asleep.
Pluton was designed and constructed on Water 7 during the Void Century, and became inactive after the war. As a reaction to the threat Pluton carried, the World Government used the existence of Pluton, Poseidon, and Uranus as the primary reason for banning Poneglyph research. What happened to it after the war has not yet been revealed, but it is supposedly hidden somewhere in Arabasta, and the Poneglyph telling its location is hidden in the kingdom's royal tomb.
Unlike Poseidon, whose ability was passed down the Ryugu Kingdom royal family bloodline, Pluton was said to be an object, meaning the only way a second instance could be created was by reconstruction. The weapon's blueprints were secretly kept in Water 7.
They had been passed down in a line of incredible shipwrights for centuries before eventually falling into the hands of the legendary shipwright Tom. The duty of the shipwrights was to guard the blueprints and prevent them from falling into the wrong hands. Also, they were supposed to use them to construct a second Pluton should the first weapon ever be revived.
Ten years before the current storyline, Spandam, the chief of CP5, appealed to the Five Elders to gain control of the Ancient Weapon in order to bring the Great Pirate Era to an end. His research led him to Tom, from whom he demanded the blueprints. Tom feigned ignorance, but when Spandam left, he entrusted the blueprints to his apprentices, Iceburg and Cutty Flam, to ensure that they would not fall into the Government's hands. Days later, when Spandam framed Tom and arrested him, and Cutty Flam suffered a seemingly fatal accident after pistol whipping Spandam, Iceberg alone kept the blueprints.
Three years later, during which Spandam had become chief of CP9, he sent four agents undercover into the city to locate and obtain the blueprints.
Passing on the Secret
Four years after his assumed death, Cutty Flam returned to Water 7, and secretly met with Iceburg, who gave the blueprints to him for safekeeping. Iceburg requested Cutty Flam that he forgo using his real name but only go by the nickname that Iceburg had given him, Franky, and leave the island to ensure that the Government would never find the blueprints. Out of necessity to avoid being arrested, he followed the first part of the advice, but refused to leave the island, much to Iceburg's ire.
At the same time that Franky received the blueprints, in another part of the world, Crocodile sought to gain control over this weapon. He struck a bargain with Nico Robin, the sole remaining person who could read the Poneglyph that told of Pluton's location, and formed the criminal organization Baroque Works to take over Arabasta in order to acquire the weapon. It took four years before the organization's purpose neared completion.
Robin forced King Cobra to lead her to the Poneglyph, but she lied to Crocodile about what it said. Crocodile easily saw through Robin's deception and stabbed her, having judged from Cobra's stunned reaction to his mentioning Pluton that the kingdom held the key to finding the weapon, and resolved to seek it out on his own, though he was defeated by Luffy and arrested before he had the chance to do so. The Poneglyph is later buried when the tomb collapses.
Water 7 Saga
Water 7 Arc
When the Straw Hat Pirates reached Water 7, the CP9 agents that had been undercover in the city for 5 years made their move, capturing Robin, who had joined the Straw Hat Pirates, and attempting to assassinate Iceburg while obtaining the blueprints. Upon discovering that the blueprints Iceburg held were fakes, they confronted the mayor, and confirmed their hypothesis that Franky had the blueprints, having discerned his true identity thanks to a passing comment when he returned to the city. They captured the cyborg, and took both him and Robin to Enies Lobby. En route, Franky learned that the rumors about Robin are untrue, and that she had no desire to revive the weapons.
Enies Lobby Arc
Not much later, Franky witnessed the Straw Hats infiltrate Enies Lobby and declare war on the World Government for Robin's sake, hammering it home that she was one of them. Seeing this, Franky reveals the blueprints, having kept them in his body the whole time, and then incinerates them right in front of Spandam, eliminating any option of building a countermeasure for the real weapon if it is ever revived.
- Pluton (Πλούτων) is the Roman name for the Greek god of the underworld Hades (ᾍδης); known as Dis Pater in Rome.
- In the anime-only special 3D2Y, another ship was shown with the power to destroy whole islands, the Groseade, though only with the assistance of Byrnndi World's Devil Fruit power, the Moa Moa no Mi. World used his abilities to enlarge the cannonballs fired from the ship's main cannon to such enormity that the destructive impact from one could blow up an entire island.
- So far, Pluton was the only known Ancient Weapon capable of being reproduced, due to the blueprints, until Franky destroyed them.