Mystery of the Zombies! Hogback's Nightmarish Research Laboratory

Fleeing the Surprise Zombies through locked corridors, Nami, Chopper, and Usopp duck into Cindry's room, where a book reveals she was once a stage actress who died during a performance. A treasure chest turns out to hold a jack-in-the-box zombie, sending them running again. The samurai Ryuma then appears, rallying the undead and cackling exactly the way Brook does.

Drawn by Hogback's laughter, the three find his laboratory and watch him fawn over a freshly assembled zombie while Cindry hopes the experiment fails. Chopper notices a number marked on the creature's arm, matching the other numbered beasts outside. Nami concludes Hogback himself builds the zombies, though Chopper still resists the idea, and a sudden laugh behind them reveals Ryuma.

Riding Cerberus through the woods, Luffy's party bickers over recruiting more strange creatures until Robin observes that everything on the island carries bandages, stitches, and tattooed numbers. Ghosts appear and drift through Luffy, Zoro, and Franky, plunging them into gloom, and Robin deduces the spirits dredge up a person's worst feelings. Pressing on, the group reaches a graveyard where zombies rise from their plots, forcing Luffy and the others to fight them off.

Ryuma debuts in this episode. Perona's Negative Hollow technique appears for the first time, as does the crew's 600,000,000 Belly Jackpot team combination. The installment draws on chapters 447, 448, and 449.