Episode 591

"Chopper Enraged - Master's Inhumane Experiments" is the 591st episode of the One Piece anime.

Short Summary
The children and the Straw Hat Pirates are in a cave with Brownbeard tied up talking about the Master. Zoro, Sanji and Brook go to look for Kin'emon, who had gone to look for his torso. The children then start to fall over in pain while asking for candy. Chopper, who had been testing them for any sickness, reveals that they had been given a highly addictive drug and are suffering from withdrawal. The children then attack the Straw Hats, who could not fight back without injuring the children, and eventually Usopp uses his Bakusui Boshi attack to put them to sleep.

Back in the lab, Trafalgar Law gives Smoker's heart to Caesar, who had sent the Yeti Cool Brothers to deal with the Straw Hats. The Yeti Cool Brothers are then shown talking to each other while Zoro, Sanji and Brook are lying unconscious nearby.

Long Summary
Franky is trying to get used to being in Chopper's body. He manages to change into Guard Point, and comments on how unstable Chopper's body is with all of its different forms. Chopper responds that he is used to it. The children roll Franky around in the snow, while Luffy rides on top of him. Sanji learns from Brook that the samurai has left to find his torso, and becomes worried for his safety as he has no means of defending himself with just his head and legs, while Sanji held himself responsible for his safety when he was just a head. Luffy grants Sanji and Brook permission to search for the samurai. When Brook asks Sanji to let him see his (Nami's) panties, and Sanji becomes excited at the prospect of taking pictures of Nami's body, Nami becomes furious and convinces Zoro to go along as well, reasoning that Sanji and Zoro's inevitable fighting rivalry will distract Sanji from doing perverted things with her body. Sure enough, within moments Sanji and Zoro are arguing, Zoro being angry that he had to come along because of Sanji's perverse new attitude, and Sanji angry at Zoro for not understanding how ecstatic the body switching situation has made him. Brook is pummeled by Nami as punishment, and to deter him from wanting to see her panties.

The rest of the Straw Hats discuss their next course of action. Nami's first priority is restoring everyone back to their original bodies, as she dislikes being in Franky's body, as she considers him to be a pervert. Franky (who has now transformed into Chopper's Brain Point) takes Nami's insult as a compliment, making a typical Franky face in Chopper's body that disgusts Robin. Franky notes that whatever they do, the children will be a burden.

Chopper finishes conducting tests on the children. Immediately after, the largest child, Sind, falls to the ground in pain. Luffy asks Chopper to heal him, but one by one the rest of the giant children fall over, holding their heads in their hands. Nami asks Chopper whether the children were really sick, to which he replies that they were not. He asks Sind whether there is something he wants, and what, if any, kinds of activities they do around that time every day. Sind, still in agony, tells him that every day all of the children would get examined and be given candy. Chopper is confused about the candy, and the other children say that the candy is strange, and tastes good. Sind says that he feels really happy when he eats it, and is convinced that it will stop the pain. Chopper, having learned the truth about the children, becomes furious. He yells at the chained up Brownbeard that the children aren't actually sick, as they had previously been told. Brownbeard maintains that although he does not know much of what goes on inside, their benefactor, Master, is a loving scientist who rescued the children and gave them free medicine. According to him, the fact that the children are in pain and have not received their daily medicine proves that they are ill, but Chopper responds with the results of his analysis — there is a tiny but sufficient quantity of a drug known as NHC10 in each of their bodies. The drug is a powerful stimulant, the use of which is tightly restricted throughout the world due to the danger it comes with and its addictive properties. Chopper learned about the drug during his time with Dr. Kureha, in which he learned that proper use of it in medicine requires using only a very tiny amount, in order to prevent addiction. Chopper concludes that the children have been given small amounts of the drug every day for a long period of time, so that the addiction forces them to remain within the research facility. Chopper demands to know from Brownbeard what his master's purpose is for the children, but Brownbeard is angry at him, believing that Chopper is merely insulting his savior.

Luffy suggests going to the research facility to find candy to stop the withdrawal symptoms, but Chopper says not to, as the candy is the means by which the drugs are delivered. Sind begs Luffy for candy, who refuses, trusting Chopper's judgment as the crew's doctor. Sind lowers his hands from his face, revealing bloodshot eyes, a runny nose and saliva dripping from his mouth, which frightens the other children. He goes berserk at Luffy for not getting the candy when he originally said he would, launching him into a nearby fallen pillar. Robin is amazed at Sind's physical strength. Usopp, while surprised, comments that this must be the strength of a giant child, but the other children reveal that none of them are actually giants; all of them were normal size when they first came to the island, and have grown more and more the longer they have remained on the island. One of the children believes that the growing must be the 'sickness' they were told they had, but Chopper disagrees, instead concluding that the rapid growth has come from experiments that have increased the levels of their pituitary hormone.

As the rest of the children gradually enter withdrawal as well, Luffy prepares to subdue them, but in order to ensure no harm comes to them Usopp instead successfully puts them to sleep with his new Sleeping Star attack. Having discovered that the children really were kidnapped, Chopper wants to save the children and return them to their parents, but Franky and Robin note that first they have to find the real culprit behind the experiments: Master. Chopper and Nami stay behind to look after the children, although Chopper expresses a desire for revenge against Master, and Nami's reasoning for staying behind appears to be fear (according to Usopp). Luffy has the largest children restrained with chains, to prevent them rampaging again. Luffy, Usopp, Robin, and Franky prepare to go to the research facility to meet Master, though Franky mentions the fact that at some point they will have to find Trafalgar Law in order to restore their bodies. Luffy seems to think it unnecessary, as he is enjoying the hijinks that have occurred.

In the research facility, Caesar Clown, Trafalgar Law, and Monet are sitting around a table. Caesar holds Smoker's heart in his hand, while Law looks on silently, with a displeased look in his eyes and a frown. Caesar is in good spirits thanks to the capture of Smoker's heart, and says he has already sent soldiers to the Marines and that he knows what the outcome of that will be. Law asks what happened to Straw Hat, and Caesar explains that, having taken Monet's warning about the Straw Hats' possible increase in strength seriously, he sent two powerful people after him: The Hitmen of the Snowy Mountain, the "Yeti Cool Brothers". The two of them are seen from behind in silhouette. They are enormous figures, each with a rifle on their back.

The scene changes to road to the mountain behind the research facility. Zoro, Sanji, and Brook are all lying in the snow. Zoro and Sanji are face-down, while Brook is face-up and spread-eagled, with his drawn sword sticking out of the snow near his head. The shot is expanded to reveal that the trio is in the middle of a trail of two sets of gigantic footprints, each barefoot and several times larger than a human body.

Anime Notes

 * The FUNimation simulcast did not use Hands Up! in this episode, due to copyright issues.
 * The scene with the children getting sick is extended.
 * The Yeti Cool brothers' introduction is extended.
 * Chopper, Franky, and Brook thinking of Master as a hero or savior is extended.
 * A comical scene between Sanji (in Nami's body) and Zoro is added.