Impel Down Arc

Impel Down arc is the 21st story arc in the One Piece series, continuing from the Amazon Lily arc. Luffy puts off finding his crew in favor of rescuing his brother Ace from the underwater prison Impel Down. With some assistance from Boa Hancock, he manages to sneak in. But fulfilling his objective and escaping the nightmarish prison might be easier said then done.

The Other Strawhats Locations
When Nami wakes up she find herself on a Sky Island. This sky island is very small and one of the people living there, an old man, tries to entertain her by showing her a wind knot and then demonstrating its applications (which unfortunately, only annoyed Nami even more). He then tells her that this small sky island is called Weatheria, an island where the scientific study of weather is conducted.

Franky finds himself on an winter island where he is almost blasted by a projectile fired by a hunter's pet cyborg dog. When a man asks him if he wants to get some warm clothes he says "I'd be a pervert disgrace!" And proceeded to perform some of his trademark poses (curiously, the men and dog who found him followed his example); Karakuri Island is the name of the place where he landed. Two townspeople tell him that he is in the "Future Kingdom Barjimoa."

Sanji, however, has landed in what would probably be the worst place for him to be. Making a mental letter to Nami and Robin, he notes that he is in hell; the transvestite-infested kingdom of Momoiro Island.

Usopp is on the Boian Archipelago in the grand line. He was attacked by many creatures withing Glinstone, where he is saved by Heracles. He is attacked by a man eating plant but Heracles saves him again. He is warned by the strange man that if he wishes to keep his life and his possessions then he should take great care within the forest.

Brook awakens on Namakura Island, the land of poverty in the Grand Line. He finds cultists around him, who think that he's a demon. They ask of him to destroy their enemies who robbed them, but Brook is only concerned about "getting back" (to his nakama). The cultist's get afraid and beg him not to go back to the "Demon Realm". They give Brook a sacrifice, a scared pretty girl. Brook asks her to see her panties, and all the cultists rush to find panties for "Satan-sama", as they call him.

In the East Blue on the bridge Tequila Wolf, Robin is questioning the foreman about the bridge, and finds out it is where prisoners or citizens of countries that did not join the world government end up. He says that they are brought there to build the bridge, which has been in construction for over 700 years. He then tells Robin to start working and it is revealed that she is shackled.

Chopper awakens in Torino Kingdom, where he was found by two gigantic birds who attempt to peck at him. Chopper, rendered immobile due to the aftermath of Monster Point, falls out of their nest to avoid being eaten. He lands in front of a couple of natives residing in the island, where it is revealed that they are actually ruled over by the birds.

Zoro suddenly crashes onto Kuraigana Island, where Perona was coincidentally transported by Kuma as well. She complains about not having any servants with her, and Zoro makes his appearance, much to Perona's discomfort. She bandages him up and puts him on a bed, and when he wakes up he asks for his swords, to which Perona says no.

The War with Whitebeard
Following Luffy's and Hancock's entrance on the ship, Hancock lets the marines know of her demand for more food, obviously for Luffy. They bring it to her, and she even uses her Mero Mero devil fruit to freeze any of the marines that peeked into her room as demonstrated by one unfortunate marine, so they would not see Luffy as a stowaway (though she probably would have turned the peeping marines to stone anyway). Luffy eats his meals, and remarks how they are delicious. The marines outside hear, and think someone else is in there and betting that if Hancock said that they would shave their hair into mohawks, but Hancock emerges with a few huge plates on a cart, remarking that she was stuffed as the marines stare in awe (and they all get mohawks).

Meanwhile, many powerful Marines, (including Smoker, Tashigi, Hina, John Giant, Kizaru, and Aokiji) are gathering at Marinford to prepare to combat Whitebeard following the destruction of their observation ships.

At Mariejoa, five of seven Shichibukai are gathered, Donquixote Doflamingo, Blackbeard, Gecko Moria, Bartholomew Kuma, and Dracule Mihawk, who are eating with a few marines. Off to the side, Garp is talking to Ace, saying that even if Ace was killed right there, it wouldn't do any good because they would not be able to stop Whitebeard, saying that have already angered the "Ruler of the Seas."

Garp continues on, expressing his disappointment that both Luffy and Ace turned to piracy when he wished for them to be marines. Ace counters it wouldn't have mattered anyway since they have the blood of a world class criminal in them. He goes on further explaining that he took his mother's name "Portgas" out of love for her and doesn't care in the slightest of his father, Dragon, claiming Whitebeard to be his only true father.

Entering Impel Down
Meanwhile Momonga's ship reaches one of the gates, spotting a pirate ship as they near it. Though Momonga leaves it be due to keeping to his schedule of reaching Impel Down on time. The pirate ship turns out to be Buggy the Clown's as his crew try to reach Impel Down as well to save their captain whose been captured. But are stopped as their dangerously close to reaching the Calm Belt. The crew argue with Alvida on continuing their mission though she reminds them of the impossible nature of it all and seems more interested in taking Buggy's ship for herself. Upon realizing she right, the crew wish Buggy luck and sail on.

We then go to the underwater prison and given a glimpse inside it horrific structure. Prisoners being tortured viciously. One new prisoner gets into a fight with another after others try to tell him how things work there. While the newbie manages to win, a minotaur-like figure beats them both with his club then throws them into a cell where a monstrous being attacks them. Also shown are various devices used for torturing further implying the nature of the prison.

Meanwhile four days have past since Luffy and Hancock left Amazon Lily as Momaga's ship has finally reached the prison. As they go past the gate, Luffy notices the strict security around the place. Hancock and he (hiding in her robe again) leave the ship to the main entrance, Momonga informing her that precautions will be made since she a former pirate to prevent chaos from happening in the prison. Among such being seastone handcuffs to nullify her power and a body search. The latter of which worries Hancock though Luffy tell her he'll deal with it. With that Hancock and Luffy enter Impel Down while a official receives news that Buggy escaped from his cell. Thirty three hours remaining before Ace's execution.

The group reach the front gate where they're greeted by the vice chief of Impel Down, Hannyabal, who introduces himself and the jail head, Domino. Hancock is taken to be searched, along the way being told of the prisoner entrance process into the prison as well as who their currently holding. Eventually Hancock is taken to a room to be searched by Domino. Before Domino can do so, Hancock freeze her as well as the camera den den mushi to stone allowing to Luffy to come of her robe undiscovered. She then tells him that as far as she can go and apologizes for not being able to help further. But Luffy disagrees, thanking her for getting him that far (even calling her by her name which causes her to swoon). Before he leaves, Hancock makes him promise not to cause a ruckus as she doesn't wish to see him get caught, which he agrees too. Hancock then leaves the room, restoring Domino in the process who has no memories of her being turned to stone. The group then proceed downward to Ace's cell, before they go Hancock sees Luffy ahead of them hiding in the ceiling mouthing "thank you" to her though she misinterprets this as "I love you" and faints much to the prison's staff surprise.

Meanwhile out in the sea, a few rather deformed beings called Bullgory slices up some sea monsters, the pieces which are then sucked into a compartment in the building. They then reenter the prison from an underwater opening as an officer praises them for refilling the prison's food supply. Back with Luffy who begins his search for Ace, noting the vastness of the prison and the screaming being heard near constantly. He passes a few cells where the prisoners inside question on why he's out of a cell then being astonished to learn he snuck in. Before they can go on further, something heads Luffy's way. It is a prisoner escapee with a few Bullgory close on his tail. They manage to catch up and slice the man in half. But the prisoner turns out to be Buggy who reconnects himself. He then realizes Luffy, forced to run as well from the creatures, beside him. After a bit of unusual chatting among one another on what to do next. They decide if they've already been spotted, they might as well called a truce, team up and raise a ruckus. With that the two attack the Bullgory together. Buggy manages to escape from the axe attack of a Bullgory with Bara-Bara Emergency Escpae and tried to defeat him with the attack Midair Spinning Supercircus, but failed to even harm him. Yet, Luffy defeats him in a glimpse after defeating all of the guards in an instant and saving Buggy, who was extremely shocked (as usual). He also remarked Luffy's ability comparing to the last time he met him. Buggy initially decides to escape but after hearing Luffy telling him about the battleships, he decides to stay. Buggy suddenly spots the arm band that Luffy is wearing and immediately identified it as the map to Captain John's treasure. He makes a deal with Luffy, he will escort him to Level 4 of Impel Down but in return, Luffy has to give him the treasure. Without hesitation, Luffy agrees and even decides to give him the arm band in advance for helping him. Buggy feels guilty for lying to Luffy but nonetheless, decides to escape from Luffy but crashes into the Goaler's room and towards the Crimson Hell. Luffy grabs hold onto Buggy as they fall. Luffy throws Buggy's feet into the ground as told and they fly towards the entrance of Level 2. Buggy explains that the hole leads to Level 2. Luffy immediately jumps down and heads towards Level 2.

Beast Hell
In Level 2, we can see in a cell anyone but Mr. 3, appearing more ragged and with facial hair than he had prior to his sentencing, who was surprised by the sudden rage of the beasts of Hell, but he doesn't care since he doesn't have the energy to be afraid anymore, since all prisoners in Level 2, Beast Hell, are their food anyway. When Luffy and Buggy arrive in the floor, they meet a Gaoler Basilisk, a snake born of a chicken and make a run in the moment. Meanwhile, Boa Hancock is introduced to the warden in charge of Impel Down: Magellan, a gigantic person with wide black wings and two goat horns with two parallel lines circling them, with a large coat. After a bit discussion with Hannyabal, he accepts her proposal of see Fire Fist Ace, for Hannyabal's shock, firstly made by Hannyabal and promptly denied by the warden, after he performed his well-known persuasion technique. Back in Level 2, Luffy knocks out the basilisk and destroy without knowing the monitor room in the process with Gear Third, for Buggy's amaze. Buggy heard the requests of the prisoners and make free them, including Mr. 3, with the keys on the floor of the former monitor room and think about making a riot there to make his escape. His thoughts are interrupted by Luffy, who pulls him by the neckband and say to him to hurry up and show the way to Level 3. Buggy retort saying he actually don't remember how to go there nor to Level 4, he lied for him only to get the Captain John's treasure map. Suddenly, he notices that the inmates returned to their cell and closed it because, as one of htem said, is useless to escape when there is still the Boss Monster. Seeing his riot plan ruined, he promptly says to Luffy that he decide to lie to him again, telling him the way to Level 3. But Luffy didn't buy it and retort saying that he thought that he said he don't know the way, and insults him as Big-nose, for Buggy's anger. But suddenly, appears Mr. 3, who says that he will help them to get to the next floor, as a part of his plan to escape from the Great Gaol. Meanwhile, at the Level where Ace is being held, we finally see Jimbei's face, talking with Ace about his real pain is laying inside his heart, which it is bursting to deal out justice to prevent the upcoming war between the World Government and Whitebeard, and he says that he would willingly give up his Shichibukai title and even his own life to stop this fighting.