Episode 591

"Chopper Enraged - Master's Inhumane Experiments" is the 591st episode of the One Piece anime.

Short Summary
The children and the Straw Hats were in a cave with Brownbeard tied up talking about the Master. Zoro, Sanji and Brook go to look for Kin'emon, who had gone to look for his torso. The children then started to fall over in pain while asking for candy. Chopper, who had been testing them for any sickness, revealed that they had been given a highly addictive drug and were suffering from withdrawl. They attacked the Straw Hats, who couldn't fight back without injuring the children, and eventually Usopp used his Bakusui Boshi attack put them to sleep.

Back in the lab, Law gave Smoker's heart to Caesar, who had sent the Yeti Cool Brothers to deal with the Straw Hats. The Yeti Cool Brothers were then shown talking to each other while Zoro, Sanji and Brook were lying unconcious nearby.

Anime Notes

 * The FUNimation simulcast did not use Hands Up! in this episode, due to copyright issues.
 * The scene with the children getting sick is extended.
 * The Yeti Cool brothers' introduction is extended.
 * Chopper, Franky, and Brook thinking of Master as a hero or savior is extended.
 * Chopper found the NCH10 in the children's sweat, not their blood.