A Duel of Swordplay! Brook vs. the Mysterious Samurai Torso

At the lake, Luffy's group have been attacked by Brownbeard and his centaur unit who's job was to intercept and eliminate any obvious intruders.
In the lab, Chopper is fighting off the hazmat soldiers who were attempting to get into his, Nami and the children's way. Sanji and Franky continue to fight off their hazmat soldiers and discovers that they look like sheep. Meanwhile outside of the lab, Brook is seen fighting against the sword wielding torso and after trying to talk to it, gives up and runs away from it.
With the G-5 marines and Smoker, the group blasts their way into the island and discovers a hidden river which they quickly enters, unaware that the river was being monitored. At the Lab, a hazmat soldier warns "Master" that the marines have almost reached the harbor. Master says he doesn't want to reveal himself to them, but his accomplice says he will greet them instead. The G-5 Marines finally reaches the shore and after Smoker rings the doorbell the marines decides to blow the door open. This was interrupted when the door suddenly opens and out comes the former supernova, Trafalgar Law. His sudden appearance makes all the marines except for Smoker and Tashigi scared. Tashigi claims he is now part of the Shichibukai after Law gave the World Government 100 pirate hearts in exchange for the position. Smoker then demands to know why Law is on the island at all since no one is permitted to set foot on the island, to which Law calmly replies with that Smoker and the marines are not allowed to enter here either.

Shichibukai! Trafalgar Law

Chopper and Nami get the children to a room with people frozen in it. Franky, Sanji and the samurai start to make their way towards Nami and Chopper. Luffy, Zoro, Usopp and Robin get attacked by the centaurs. The centaurs attempt to sink their banana boat. Smoker and Tashigi claim that the signal from earlier came from Punk Hazard and Trafalgar Law states that the Marines often tend to forge messages. The Straw Hat Pirates and the children see Law and the Marines, at the sight of them they run back into the building. Law uses Room and Tact to lift a marine warship in order to prevent the marines' escape. Smoker and Law then prepare to fight.

A Big Pinch - Luffy Sinks Into the Cold Lake

Luffy, Zoro, Usopp and Robin try to get to the ice side of Punk Hazard but their ship gets capsized by Brownbeard. As Brownbeard's troop prepares attack them again, Zoro gets ready to destroy their bullets but gets dragged down by sharks. At the last second, Brook saves them and defeats Brownbeard's shooters. Once Luffy and the gang got out of the freezing water after killing the sharks, they opted to take the centaur's warm coats.
The Straw Hats who rescued the children attempt to go back into the building to find another escape route, but their "hearts" get switched by Law, making them swap bodies. Law then returns his attention to the marines and destroys their ship. The G-5 marines attempt to contact marine headquarters about Law but he takes away all their Den Den Mushi. Smoker then fights Law and warns his men to stay back from the fight unless they want to get cut to pieces (which they did). Feeling useless in the situation, Tashigi attempts to strike the Shichibukai but was promptly bisected.

A Collision! Law vs. Vice Admiral Smoker!

Law was going to to cut up Tashigi into little pieces but Smoker saved her and started fighting against Law. Luffy, Zoro, Robin and Usopp are riding on top of Brownbeard after defeating him and his centaurs and stealing their coats and are heading towards the building Brook told them about. Nami, Sanji, Franky, Chopper, the kids and the samurai head try to escape from the Law and the Marines while figuring out what Law did to them. In front of the labratory, Law defeated Smoker by taking his heart.

First Meeting in Two Years! Luffy and Law

Tashigi tries to see what happened in the fight. Luffy's group sees the flying warship. Luffy sees Law and thanks him for saving him two years ago. Law says that they aren't friends and Luffy agrees since they were both after One Piece. Law remembers the past between him and Luffy when Law saved him at Marineford. Luffy sees Smoker on the ground. Tashigi cries over Smokers body and attempts to kill Law but he switches their hearts. Meanwhile, the kids from the lab complain about the cold so the samurai uses his devil fruit to give the kids and the Straw Hats warm clothes. Luffy's group then meets up with the other group behind the lab.  While going over what happened Robin reveals that Law became a Shichibukai two years ago and the samurai reveals that Law is the one who cut him in thirds and reunites with his legs. Law meets up with Caesar Clown who Smoker speculated was behind everything on the island.