The Underground Round Up (Japanese: マルマインだいばくは！？ Electrode's Tremendous Blast!?) is the 33rd episode of Pokémon: Adventures on the Orange Islands.
After saying goodbye to Lapras, Ash and co. arrive on Hamlin Island, which has a ferry line that goes straight back to Pallet Town. Unfortunately, the town is deserted because of the many Electrode inhabiting the city. Lucky for our heroes they meet a man named Poncho who specialized in Electrode Rangling. Soon Team Rocket appears to capture the Electrode by any means necessary, by order of the mayor. Will Team Rocket have their way or will Poncho save the day?
The heroes are on Hamlin Island, where they'll take a boat to Pallet Town. Ash already imagines mom's specialties, while Tracey meeting Prof. Oak and Misty beinging the GS Ball. The heroes are about to cross the bridge to the ferry, but see a sign saying it is too dangerous to cross it. The gang is about to cross the bridge anyway, but seeing an explosion on the bridge they change their minds. Instead, they take a small boat and paddle to the island. They go through the town, but see and hear nobody. They enter a building and Misty leaves her Togepi for a while. Tracey sees the ferry and Ash attempts to open the door, but it is locked. Togepi comes out of the building and sees a Voltorb, then follows it.
Misty sees Togepi is missing. The heroes search for it and find it playing with the Voltorb. Ash checks it via Poké Dex and learn Voltorb may explode without warning. Misty goes to get Togepi, but Togepi does not want to leave Voltorb. Ash and Tracey tell Misty they feel they are not alone. Soon, they see Electrode coming out. Ash tells Misty not to sneeze or breathe, but Misty gets angered as she has to breathe. She tells Togepi it can play by the ferry, so the heroes move quietly, not disturbing the nearby Electrode. A signboard falls down, causing the Electrode to be disturbed. The heroes run as the Electrode explode. The heroes soon find themselves surrounded by the Electrode.
However, a man appears, telling them not to move, sending Diglett. The Diglett dig holes beneath the Electrode, causing them to fall down and they explode in the holes. Later, the gang asks the man why are there so many Electrode and so little people. The man tells that due to an experiment to generate power, the Voltorb escaped one night and multiplied. The island was filled with them and they evolved into Electrode. The island began to be too little for all of them and they started exploding. The people left the island. Ash asks what of the ferry, but learns that it does not function anymore. Tracey asks the man why is he here if the island is dangerous. Ash thinks he is a thief trying to steal what he can, but Misty tells Ash to apologise for that statement. The man introduces himself as Poncho, a Diglett Rancher who has been hired by the mayor.
He tells that he trained his Diglett to dig under the island to a field at the next island, where they roam freely and do not explode. He thinks his way is better than let them explode. Ash thinks the Electrode think that, too. Poncho hears that people tell his way costs too much and is too long. The phone rings and Misty gets it, then passes it to Poncho. Poncho is disappointed, as he heard the people hired someone else to complete the job, as he should've been given few more days to get the Electrode away. Misty wonders who'd that be. Poncho knows these people will be fast, but the Electrode will blow up once caught. Suddenly, they feel a vehicle arriving and arrive in front of it, only to see Team Rocket emerging from it.
Team Rocket tell them the mayor hired them to complete the work. Ash doubts them, but Poncho sees the contract they hold has the mayor's seal on it, making them legit. Misty wonders why would they capture the Electrode, but is told they will use them for their own needs. They touch the Electrode and they explode. Poncho knows they want to tire out the Electrode so they can capture them with no resistance. The heroes are frustrated, as they cannot do but watch as Team Rocket takes the Electrode. This causes the Electrode to surround Team Rocket's vehicle. While Jessie and James are scared, Meowth tells it is where they wanted to have them. Poncho feels the Electrode are very angry and will explode. The Voltorb that played with Togepi comes in front of the vehcile. Jessie is annoyed by this one, but James and Meowth feel generous and want to catch it.
Togepi moves its arms and uses Metronome, causing it to jump. Misty feels it wants to attack, but Tracey thinks it is too young for that. Voltorb evades the robo arms, so Togepi and Pikachu go to help it. Pikachu uses Thunderbolt, but it does not do any damage, as Meowth knows they had to deal with shocking Pokémon and have an electric-proof vehicle. Team Rocket are about to attack, so Poncho, disgraced by Team Rocket, sends Dugtrio. Dugtrio digs out a tunnel, causing Team Rocket to fall in the tunnel. While Poncho is glad Team Rocket are out of the way, the work is not yet finished and sends Diglett, who dig tunnels to get the Electrode away from the island. Team Rocket are very disappointed their plan did not work and get swept away by the Electrode, who move through the tunnel.
The heroes see from the balloon the Electrode enjoy this field as their new home. Voltorb comes out of the balloon and Togepi follows it. Togepi sees Voltorb wants to stay and cries. Misty tells it friends have to say goodbye, but they are still friends in their hearts. Next day, the people moved back in. Poncho admits the mayor gave him a bonus and the key to the city. Misty remembers his line "those three are a disgrace" and compares a movie hero'd say that. Poncho blushes, telling he is no movie hero. Ash tells he is their hero and invites him to come to Pallet Town. Poncho thanks him, but tells he has to take care of Electrode. The heroes wave goodbye to Poncho, while behind them Jigglypuff appears.
- "Those three are a disgrace to the Electrode Rangling profession." - Poncho about Team Rocket
- Poncho is based off Clint Eastwood.
- Poncho in the end of the episode says he's not a movie hero, another reference to Clint Eastwood.
- The "Who's that Pokémon?" in this episode is Kingler.
- Second appearance of Diglett. First was in IL031: Dig Those Diglett!, and the third would be in the Johto episode JE102: Plant It Now... Diglett Later.
At the end of the episode, as Togepi is saying goodbye to Voltorb, the vocal effect added to Voltorb's voice is missing.