Chapter 851 is titled "Moist Cigarette".
20th Anniversary Special Color Spread: The Straw Hats are underwater in blue and black outfits, surrounded by sea creatures.
Pudding gleefully looks forward to shooting Sanji and his family down, revealing her revolver, which carries bullets strong enough to penetrate through the Vinsmokes' genetic armor. She then wonders how Sanji will react to her true nature, mockingly making shocked faces. Meanwhile, Sanji stands outside and cries, being unable to light a cigarette due to the rain.
In the Room of Treasure, Big Mom easily overwhelms Brook with Zeus and Prometheus, though Brook continues getting back up. He reveals to Big Mom that he is determined to get her Road Poneglyph at any cost in order to make their journey here worth something, even if they fail to get Sanji back. Meanwhile, in the Mirro-World, Brûlée is revived, and she reveals that Chopper and Carrot can ask the mirrors where they lead to. After asking some nearby mirrors about Sanji, Carrot starts drawing Sanji's face.
Back in Pudding's room, she extracts and removes Reiju's memory of their encounter with the power of the Memo Memo no Mi. In the Prisoner Library, Opera receives orders to extract Lola's location out of Nami, and he threatens to torture her for noncompliance. However, Jinbe arrives, punches Opera, and prepares to free Luffy and Nami.
Pudding continues laughing about the planned massacre of the Vinsmoke Family, saying their blood will stain the ceremony hall, although she warns Reiju to be careful and not get any blood on the wedding cake, or else Big Mom will get mad and destroy the ceremony hall. Pudding pulls out a Walker .36 Caliber Percussion Revolver which she will use to shoot the Vinsmokes, and she reveals that it is loaded with Candy Jacket bullets that can penetrate armor, meaning that it can also go through the Vinsmokes' iron outer skeletons. Pudding looks forward to seeing Sanji's expression when she pulls the gun on him tomorrow, and Nitro and Rabiyan laugh with glee. Pudding makes a few shocked faces to mockingly predict how Sanji will react, and then asks Reiju if she wants to know how Sanji proposed to her today. Pudding mocks Sanji's injured face that was under his mask, and mockingly reenacts his proposal, calling it cheesy. She calls Sanji ugly and a failure, saying that at least she wanted a proper prince. Outside, Sanji tries lighting a cigarette, but the rain prevents it and tears start streaming down his face.
In the Room of Treasure, Big Mom asks Brook why is he getting up again, wondering why is he going after her Road Poneglyph and not after Sanji. As Brook struggles to get back to his feet, he replies that since Sanji is a kind person, he knows that his crewmate will likely sacrifice himself and not get rescued for the sake of others. As he stands before Big Mom, who has Zeus on her left hand and Prometheus on her right, he says that on the other hand, Luffy is someone who will break through any barrier to achieve his dreams, so Sanji's situation should be decided just by those two. Big Mom infers that Brook is then here because he has nothing better to do, but Brook replies that his mission is just as important. Should they fail to rescue Sanji, they can at least honor him by acquiring the Road Poneglyph and making this journey worth something. Big Mom retorts that losing Sanji is not the worst that could happen to them, as they could easily die on this journey. However, Brook says that death should never be considered when making a plan, calling Big Mom "young lady" as he raises his sword.
In the Mirro-World, Carrot manages to revive Brûlée by tickling her, and Brûlée finally gives in to the duo's demands. Carrot asks her where the castle is, and after she swears revenge under her breath, Brûlée states that she does not remember and tells them to just ask the mirrors. Carrot and Chopper ask which mirrors lead to the castle, and the mirrors that do respond to them. Chopper asks if any of them are reflecting Luffy, Nami, Brook, Pedro, or Sanji, but none of the mirrors know who they are with the exception of one, whom Sanji had just passed by. However, Carrot tells Chopper to leave it to her, as she claims to be skilled at drawing and plans to draw portraits of their teammates.
Back in Pudding's room, in order to prevent Reiju from dying of blood loss or revealing her plans, Pudding reaches into the side of Reiju's head. Her hand penetrates Reiju's head, and pulls out a strip of film containing Reiju's memories. Pudding reveals that she ate the Memo Memo no Mi, which allows her to turn people's memories into film strips and alter them. She then cuts out Reiju's memories of their encounter and replaces them with a soldier's memory of being hit by a stray bullet, in order for Reiju to explain how she was shot. Pudding then dons her sweet persona as she hopes they both have a good time at the wedding ceremony, and she calls a soldier to take Reiju to the infirmary.
Inside the Prisoner Library, Opera watches as Luffy continues pulling at his stake, and Nami continues crying out as more blood comes from Luffy's wrists. Opera then tells Nami that Big Mom ordered him to get Lola's location from her by the end of the day, but Nami refuses to sell out one of her friends. Opera then prepares to torture Nami by shooting her with a crossbow once every five seconds until she confesses, and a frightened Nami begs him to stop the escalated threats. Luffy shouts at Opera to stop, and tells Nami that he will have ripped his hands off in the next five seconds, which Nami does not want to happen either. Luffy and Opera both tell Nami to stop being so difficult, when someone suddenly enters the Prisoner Library. Opera tells the intruder that he is not allowed to enter castle grounds at the moment, but the intruder simply apologizes before preparing a punch. The intruder, Jinbe, then punches Opera in the stomach with great force, causing him to skid onto the ground in shock. Luffy, Nami, and Opera are all bewildered to see Jinbe, and the former two wonder why is he here. Jinbe replies that he heard the two of them were captured, and they can talk later, but now he is preparing to free them.
- Pudding reveals the gun she will use to shoot Sanji.
- According to Pudding, the gun that she used to shoot Reiju is loaded with material that can penetrate through the Vinsmoke's iron outer-skeleton.
- Big Mom overwhelms Brook with Zeus and Prometheus.
- Brûlée is revived and reveals that Chopper and Carrot can speak to the mirrors in the Mirro-World.
- Pudding is revealed to have eaten the Memo Memo no Mi, which allows her to alter people's memories.
- She removes Reiju's memories of their encounter.
- Opera received orders from Big Mom to find out Lola's location from Nami.
- Jinbe breaks into the Prisoner Library and attacks Opera in order to free Luffy and Nami.
- For unknown reasons, Jinbe is not allowed on the castle grounds.