Pikachu Re-Volts (きえたポケモンたちのナゾ！ The Puzzle of the Disappearing Pokémon!) is the 6th episode of Pokémon: Adventures on the Orange Islands season.
As soon as Ash and friends arrive on Mandarin Island and notice that all the Pokémon hate their trainers. Pikachu and Togepi falls under the dark spell as well, turning against Ash and Misty. Team Rocket arrive too and Meowth runs away. They soon realize it was the work of Cassidy, Butch and their new Drowzee. Can Ash stop Cassidy and Butch?
As Lapras swims, Ash wonders when will they eat. Using the binoculars, Tracey sees Mandrain Island. Ash sees as well, but he and Misty see it looks like buildings floating on sea. Tracey tells Mandarin Island has a big city, with many theaters and skyscrapers. Misty is disappointed it is not a tropical island, but Ash does not care as long as there is something to eat. They are being watched by two people, who know him from before and demand revenge. When they arrive, Ash calls Lapras back. Suddenly, a group of people are being pressed by their Pokémon. Ash and Pikachu go, but Pikachu is affected by something and stops. Pikachu turns to Ash, with a sour look on his face. Togepi comes to him, with the same look. Ash asks if something is wrong and gets attacked by Pikachu, knocking him, Misty and Tracey out.
Ash goes to Pikachu, but gets stopped by Magnemite, who electrocute him. Ash tries to resist this and goes to Pikachu. The Voltorb explodes and suddenly, the Pokémon are gone. Ash yells "Pikachu!", but there is no reply. Jenny comes, being explained what happened. Jenny heard of this trouble and suddenly, Gastly appears, so Jenny pushes it away. They contact Oak and Ash wants to find Pikachu as soon as possible. Oak asks if he knows where to look, but seeing he does not know, Ash calms down. Jenny believes that it is a psychic-attack at doing, as her Gastly is not affected by it. Oak responds there is some truth to it. Tracey thinks a Psychic Pokémon is doing this, causing Ash to shake him, trying to know whom. Tracey tells him to calm down, although Ash knows Pikachu has never behaved like that. Thinking if they find the source, Ash will find Pikachu, so they go to search.
Team Rocket came to a large building. Jessie and James want to enter it, but Meowth scratches them, reminding them they need to capture Pikachu. As Jessie goes to attack, Meowth defends himself, but gets affected, having a gloomy look on his face and runs away. They come to a building, where Meowth goes in a hole. Meowth enters and tells he is here to serve. Two people see it is a talking Meowth, and those two are Cassidy and Butch. Jessie and James enter through the same tunnel Meowth did and see Cassidy and Butch. Jessie is surprised to see Cassidy and James also, to see Butch, but calls him Mooch, making Butch disappointed.They all tell the motto and get exhausted. Cassidy tells Jessie she might get kicked off Team Rocket, but it is only a rumor. James asks if something was told about him, but Jessie pulls him, thinking Cassidy started this rumor. Butch and Cassidy clarify that the boss himself has come to them and paid the fine to get them out of the prison.
Meowth comes to Butch and Cassidy. James tells Meowth to remember who are his friends, but Meowth ignores. Cassidy and Butch point to the Pokémon collection, all who have malicious look on their faces, all under their ownership. Jessie sends Lickitung and Arbok, while James Weezing and Victreebel, hoping to steal from them. When Victreebel was sent, it bites James. Suddenly, a Drowzee, equipped by some machines, appears. Jessie tells the Pokémon to attack, but they are out of their control. Butch tells that Drowzee broadcasts psychic waves, which are sent via the antennae, controlling any Pokémon. Due to this, Cassidy and Butch order Jessie's and James' Pokémon, along with Meowth, to attack Jessie and James, which they do.
Jessie wakes up and finds Ash, getting surprised. Misty bandages James' arm, even if he finds it rough. Ash tells Gastly found them on the street. Jenny believes there is a connection between them and the unusual activity, while Ash wonders how Meowth is not with them. James explains Meowth, like their own Pokémon, were taken away. Jessie and James would like to say, but they don't want to help the police. However, Ash stops them, saying that all Pokémon are in trouble. James and Jessie are convinced, thinking they can help only this time.
Jessie and James come to the building, telling Butch and Cassidy they have a peace offering - many Poké Balls. Butch and Cassidy let them in, although they know Jessie and James are not like them. Jessie and James push the cart, as Ash, Misty, Tracey and Officer Jenny appear out of it. They see Drowzee is controlling the Pokémon, so it uses the psychic powers to command the Pokémon to attack. Officer Jenny's Gastly uses Psywave, negating Drowzee's psychic powers, but the attack is stopped. The Pokémon attack, though Ash goes to Pikachu. Gastly appears and negates the attack, while Ash tries to reason with Pikachu. Pikachu uses Thunderbolt on him, but Ash smiles, telling Pikachu to catch him. While Ash gets hit some times (making Butch and Cassidy surprised), he stops and Pikachu uses Thunderbolt. While he hits Ash, this causes the machines Ash was standing to explode. Drowzee does not have the control over Pokémon, as they are being confused where they are.
Misty reunites with Togepi, while Jessie and James are glad Meowth is back to himself. Ash is happy Pikachu is back to normal. Cassidy and Butch attempt to get the Pokémon, but are distracted by Weezing's Smokescreen. Gastly destroys the gate and the Pokémon go out of the building. Butch and Cassidy appear, wanting battle with Jessie and James. They accept the challenge, being a 2-on-2 battle. Ash appears, wanting the 3-on-3 battle, wanting justice what they did to the Pokémon. Jenny warns them Drowzee is still powerful. Pikachu uses Thunderbolt, though Drowzee teleports to Pikachu. Arbok goes to bite, but Drowzee teleports once more. Victreebel, Lickitung and Weezing go to Tackle, but are pushed away by Drowzee's Mega Punch. Ash and Pikachu go attack though Butch and Cassidy still plan to use the antennae, so Cassidy declares the Metronome. Drowzee pushes its fingers left and right (and so does Togepi). Pikachu goes to attack, although Togepi releases its powers.
With a huge blast, the building explodes, so Butch and Cassidy are arrested. Next day, the heroes receive the awards of becoming the honorary citizens. Jenny tells they would've given to Jessie and James an award, but they are not present. Team Rocket heard this and even if they did the right thing, they know wrong is where they belong. As the heroes depart, Tracey notices Jessie and James are only on the winning side when it is required. Ash responds that even they can win some of them and the heroes laugh.
The "Who's that Pokémon?" in this episode is Kangaskhan.