Summary:
The chapter opens with the crew wondering how deep the ship has sunk beneath the ocean. Usopp notes that the light barely reaches them anymore. Franky said they were beyond a level called the euphotic zone and about to be beyond another level called the dysphotic zone, saying they were probably about 1,000m below the surface. Nico Robin notes how quiet it is, completely different from a submarine and how it reminds her of flying in the sky. The ship passes a small pod of blue whales. Brook cries because they remind him of Laboon. Luffy thinks they look like Whitebeard and waves at them. While this is happening, the Caribou Pirates ship quickly approaches the Thousand Sunny from behind, being towed by a shadowy sea monster. Caribou is heard gathering the crew and preparing them for the coming attack. Caribou appears aboard his ship and says he wants to announce their names to the world by taking the straw hat heads to show the world.
Back on the Sunny, Usopp sees something bearing down on them from the six o’clock direction of the ship (directly behind the ship). Thinking it’s a sea monster, he tells the crew that a shadow is heading straight for them. Caribou’s ship soon catches up and sails alongside Sunny. The ship looks like it’s trying to crash into Sunny, but it’s actually trying to touch the bubble roofs. The Straw Hats wonder whose ship it is. Caribou leads the charge. Just then, Nami recognizes the monster pulling the ship as Momoo, the sea cow from the Arlong Pirates. Momoo sees Nami, Sanji and Luffy, all three of them remember from the past. Remembering the beatings he received from Luffy and Sanji, he swims back the other way out of the horror, dragging the ship with him, but not before Caribou (and only Caribou) managed to get aboard the Thousand Sunny. The Caribou pirates, who are still on the ship, are completely stunned by what just happened. They also wondered why there was a sea cow attached to their ship.
Caribou, unaware that he has been left behind, orders his crew to introduce themselves by beating all the Straw Hats. He immediately realizes that he is the only one of his crew aboard the ship and immediately changes his tune. Franky picks him up with one hand, Caribou begs him not to throw him into the ocean, calling them gentlemen and saying that human life is not something to be wasted and that God is watching over them. Instead of throwing it into the ocean, Franky simply throws it over one of the ship’s side rails. Zoro asks if he was the captain of the ship that was passing by. Caribou, realizing who asked the question, immediately denies it, saying that he’s just a human bullet for the crew and that he’s sick of being on that ship. He then asks the Straw Hats if it would be okay if he rode with them for a while. Chopper believes him and says he could be the victim. Usopp ironically calls everything Caribou said a lie, surprising Chopper. Nami asks Caribou why they had a sea cow towing their ship. Caribou calls her a cutie pie and asks her if she is the “cat thief” Nami. Sanji then intervenes, kicking him in the face and pinning him to the wall, saying that he has no right to look at Nami with his contemptuous eyes. He then prepares to tell Nami that everything is fine. Before he could finish his sentence, however, another nosebleed erupted. Usopp says his nosebleed is becoming a pain in the ass. Chopper suggests they rehabilitate him with low-intensity imagery. Caribou explains that they caught Momoo in the area and says that letting a sea monster tow their boat is the mark of a professional undersea traveler.
The scene switches back to the Caribou Pirates for a moment, the crew trying to tell Momo to stop, asking him what happened. Coribou then says that Caribou will save them just in case.
Back on the Sunny, Luffy asks if anyone has seen a sea cow anywhere, and then Nami asks him what he’s planning. Usopp then notices that the ship has changed direction and asks Nami if it was okay. The scene changes for a moment before she answers. Luffy pokes the tied up Caribou with his stick. Caribou revises his plan. Since he can get off the ropes whenever he likes, and since he can’t fight nine people at once, he thinks it would be best to observe the crew and wait for an opportunity to kill them one by one. He starts to come up with another idea but is cut off. Nami then said that the slight shift was fine as they were supposed to be southwest of the log needle. Luffy asks if it wouldn’t be faster to go in a straight line while Brook says he’s getting cold and is about to say he has no skin, but Chopper beats him to it when he says it’s awesome because he has no skin. Nami explains that if they continue straight, they would just be swallowed by the currents and might hit a volcano or a seamount before completing their descent. Usopp says that the Grand Line currents have always presented some danger and asks if there is one that can be taken.
Nami replies that there is only one and tells everyone to put on their coats, saying that the journey will be much colder. Zoro asks if they went somewhere cold, he says he thought they were going to the deep sea. Franky corrects him that the water in the deep sea is cold. Just like in a bathtub, the water is colder at the bottom than at the top. Brook then adds that cooler surfaces have so-called Deep Currents, large ocean currents normally invisible to the naked eye that move in a completely different way than surface currents. Franky adds that all currents on both levels will eventually connect and reconnect regardless of depth or whether they travel from east to west, comparing it to a giant dragon. He also added that currents travel all over the world without ever breaking. Brooks then says that he has heard that the Deep Currents move very slowly along the ocean floor, and that once someone gets that deep, it can take almost 2,000 years to get back to the part of the sea that gets sunlight. He then adds that there are many legends surrounding the streams about monsters, curses and spirits. This excites Luffy and scares Chopper. Nami says that to get there they need to ride a down current that will take them from the surface current to the deep current. Chopper asks how they find such a place. Robin replies that the cold water will move down like in a bathtub. Usopp then concludes that they are going to a place where ocean currents lose their heat. Nami describes the red line as a group of adjacent islands, each with a different season. They are heading for the climate zone where the winter islands are and say that this area meets another prerequisite for the currents to decrease.
Luffy, suddenly intrigued, asks what the premise is. Nami says it’s the salinity or salt content of the seawater. Luffy said he was playing salinity all along and Zoro said he always wanted a fire sword. Luffy then asks Zoro how far he was sent away. Usopp and Chopper ask Nami to continue explaining salinity and ocean currents. Surprised by their enthusiasm, Nami goes on to explain that a downdraft requires the presence of cold, heavy water, and that sea ice exists in cold regions. Before he can continue to explain, Luffy, Zoro, Usopp, and Chopper are all seen drinking tea, simultaneously saying, “So it’s a mysterious stream, huh?” This infuriates Nami to no end and yells that they should have kept quiet and gone from the beginning. Brook offers to sing. Franky then calls out to her from the bow of the ship saying that “it” has appeared. Everyone goes to the bow. Luffy asks what the stream looks like. In response to seeing this, Franky says, “Mother Nature really knows how to get things done.” Sanji asks what it is. Nami replies that it’s called the Downward Plume. It’s like a huge underwater waterfall. Everyone stares at the Downward Plume in shock and awe. Robin comments on its massive flow, wondering how many hundreds of meters it is in diameter. Brook said hearing it and seeing it are two completely different things. Usopp was afraid that since it was too dark to see the bottom, he assumed the ship would crash and break up on the ocean floor. Nami questioned the safety of the current while Franky assured her that a ship born of Adam Wood could survive anything.
Caribou, who had been silent the whole time, gets up and tells the Straw Hats to turn around immediately, that something is wrong. Zoro looked at him and forgot he was there. Luffy says he sees a monster at the bottom. Caribou says he has never heard of such a type of sea monster living in a place like the Downward Plume. He described the creature as follows: “I’ve never heard of that thing living in these waters!!! ……!!! That legendary demon that roams the vast ocean and never tires of the carnage it leaves behind in its wake…!! Enemy of all mankind!!!” The monster in question is the kraken, a giant, mythological octopus. Franky adds that he crushes all the ships in his tentacles and that he had to take all the ships that have left in the last few days. As Usopp comments on his gargantuan size, Chopper foams at the mouth in shock. Caribou said that it must have been the prey of ships trying to get through the down current, and that he had never heard of such a thing happening before. He begs Luffy to come back and tells him to wait a few more days. Luffy simply calls him loud and tells him to shut up. The chapter ends with Luffy saying that he will make the kraken his pet.