The Straw Hats' next destination is Fishman Island, but first they must traverse the dreaded Florian Triangle which is known for many eerie and mysterious things such as disappearing crews, conversational skeletons, and a floating island full of zombies and other horrors.
The Thousand Sunny gets flung into the foggy Florian Triangle and the Straw Hats encounter a ruined ship. Speculating as to whether there are ghosts aboard, it turns out the pirates are not far from the truth.
Brook bids the Straw Hats farewell, and they decide to explore the nearby ghost island Thriller Bark. Freakish danger awaits the landing party the moment they arrive, and, back on the Sunny, the rest of the crew is harassed by an unseen foe.
While staying at Hogback's eerie mansion, Nami is assaulted by an invisible figure in the shower. It does not end there as Usopp battles haunted paintings with a handful of candles. Meanwhile, the rest of the Straw Hats finally make landfall.
The Straw Hats learn that the head honcho on the island is one of the Seven Warlords, and he has concocted a shadowy scheme. As Absalom rallies the zombies, the master of Thriller Bark awakens.
Nami, Usopp, and Chopper manage to escape their coffin but find themselves in a garden surrounded by animal zombies, including one acting remarkably like Sanji. It also seems that one by one, the Straw Hats are disappearing.
Lola attacks Nami out of ignorant jealousy, but the Sanji-esque zombie plays interference. Meanwhile, with Luffy captured, and Franky and Robin left to face a massive spider monkey, a familiar bony figure falls from the sky.
Gecko Moria takes his next step toward his goal of eventually becoming king of the pirates by creating the ultimate zombie. Luffy's shadow in hand, Moria begins the revival of the much-anticipated number 900.
Dead for 500 years and left in a deep freeze since, Oars awakens, fueled by Luffy's shadow. Soon after, Nami, Usopp, and Chopper are discovered hiding inside Perona's pet bear, and Absalom abducts Nami for his demented marriage ceremony.
The Straw Hats regroup on the Sunny in a pitiable state, but not before Brook leaves Franky with some valuable information. In addition, they now know of the promise Brook made to a certain friend fifty years ago, someone the Straw Hats know well.
Oars' entry into the fight suddenly changes everything! Then, when Perona attacks, only one of the pirates seems to be immune to her negative powers. Due to his glass-half-empty personality, Usopp might have what it takes to defeat the Ghost Princess.
Sanji crashes Absalom's sham of a wedding, the fire in his heart burning brightly as he rescues Nami. A curious connection between Sanji and the Clear-Clear Fruit is revealed, and he vows to defeat Absalom for ruining his lifelong dream.
After getting the stuffing beat out of him by a zombie teddy bear, Usopp summons his sharp-shooting alter ego to help him discover the secret to defeating Perona! He reaches deep into his devious bag of tricks to even the odds in this spooky battle.
Zoro stands in for Brook and duels Ryuma, the swordsman zombie from faraway Wano. In the mansion, Chopper's former respect for Dr. Hogback is completely erased after coming to realize the man's twisted views on life.
With Oars now a fully obedient zombie, Gecko Moria takes his leave while instructing the giant to hunt down the pirates, whose wanted posters are sewn onto his arm. One by one, the Straw Hats' battles are interrupted by Oars' march around Thriller Bark.
The Straw Hats sans Luffy are faced with the insurmountable task of taking out Oars. To knock him down, Franky decides they will need to use his newly developed tactic. But as they begin "docking" onto one another, a slight problem arises.
While the Straw Hats continue to wear away at Oars, Nami confronts Perona attempting to escape on board the Thousand Sunny, but the sudden appearance of a large, mysterious figure soon makes her efforts moot.
To give Luffy a fighting chance against Moria, Lola and her pirate crew propose a plan to fight shadow with shadow. Meanwhile, Gecko Moria uses his abilities to enhance and manipulate Oars’ massive body.
Moria’s strange combination with Oars defeats the Straw Hats one after the other. They are at their breaking point when a powerful figure swoops in and takes up the fight in their stead. The hellish creation: Nightmare Luffy!
Oars recovers from Nightmare Luffy's assault, but the Straw Hats all get back on their feet and launch a final devastating attack on Oars. Morning fast approaches, and Moria is far from finished, ready to use his ultimate technique.
Moria’s defeat returns the shadows of all his victims. However, one Warlord remains on the island, and he has orders to terminate the Straw Hats and everyone else in the area. A lone Zoro faces Kuma in vain and is presented with a deadly choice.
Brook recalls his past, thinking back on the time when the small whale Laboon started following his pirate ship and befriended the crew.
At death's door, the Rumbar Pirates sang "Binks' Brew" one last time and recorded it in a tone dial, hoping to one day deliver it to Laboon. With their new crewmate and musician Brook on board, the Straw Hats bid farewell to Lola’s crew.