Chapter 947 is titled "Queen's Gamble".
Luffy is unable to defend himself and Hyogoro from Big Mom, and she rampages around the Prisoner Mines. Queen develops a plan to attack her when she reaches him, and when she does, he slams into her from above in his brachiosaurus form. This causes Big Mom to regain her memories, but she immediately falls asleep afterward, and Queen has her chained up before taking her to Onigashima. Babanuki is left in charge, but Luffy decides to battle the remaining Beasts Pirates and take control of Udon.
Luffy recognizes that what he did to remove his and Hyogoro's death collars was the same technique that he saw Silvers Rayleigh use to remove Camie's exploding collar on Sabaody two years ago. However, since he used it in the heat of the moment, he is not sure how to activate it at will. Hyogoro notes that what Luffy just did was superior to what he had been trying to teach him, and so if Luffy could do that, he should be able to protect him from the attacking Big Mom. Luffy attempts to have his Haki flow through his hands, but Big Mom instantly overwhelms him and sends him and Hyogoro crashing into a wall.
Luffy worriedly apologizes to Hyogoro as he pulls him out of the wall, but Hyogoro reveals he used Haki to protect himself just in case. He tells Luffy that there is another step in concentrating and projecting Haki, which is the ability to destroy objects from the inside. This is what Luffy did to destroy their collars, so he is certainly capable of using advanced Haki, he has just not realized how to do it. Luffy and Hyogoro are then separated by Big Mom, who pursues Luffy into the neighboring Prisoner Iron Factory. The Beasts Pirates left in the Mines worriedly wonder how Big Mom can be stopped when Queen suddenly gets up. Having no intention of giving up, Queen tells his subordinates his plan, with the idea that Big Mom in her rampage would eventually circle back around to where they were.
After some time, Queen is proven right as Big Mom chases Luffy back into the Prisoner Mines, and he waits on top of a cliff in his brachiosaurus form. Big Mom sees the o-shiruko bowl left as bait on the ground and stops to look in it, and Queen takes this chance to dive on her, landing headfirst on her with his immense weight. However, Big Mom does not give way from the impact, and the force of the blow causes her to regain her memories and realize what has happened. She then recognizes Queen, and with her aura completely different from before, the Beasts Pirates have no escape from her wrath. However, Big Mom then falls asleep, and Queen immediately orders for her to be bound in pure Seastone chains and injected with their heaviest anesthesia. Queen has most of his subordinates accompany him and Big Mom on a ship heading for Onigashima, leaving Babanuki to lead the small remainder of the crew in restoring order to the prison. As Queen's ship sets sail, the prison gate starts closing, and Tama decides to slip inside along with the unwilling Momonosuke. With communications still cut off, Luffy prepares to take down Babanuki and his forces. When Babanuki thinks out loud that Luffy was now free, Luffy remarks that he had always been free and will now take over the prison.
- The flashback to Chapter 504 reveals that Rayleigh removed Camie's slave collar by using advanced Busoshoku Haki.
- The concept of advanced Busoshoku Haki is further explained. It can be used to attack an enemy from within.
- Luffy manages to use the advanced Busoshoku Haki technique but has not fully mastered it yet.
- Queen recovers and attempts another attack on Big Mom.
- Momonosuke and Tama enter the Prisoner Mines.
- Luffy decides to take over Udon.