Several months have passed since Ash left his hometown of Pallet on his Pokémon journey. After lots of adventures and discoveries, Ash and his friends find themselves somewhere in the mountains en route to Fuchsia City where Ash will challenge the Fuchsia City Gym leader. Ash is confident that when he gets there, he will get his next badge.

Brock tells his friends that the map says the Fuchsia Gym's on the other side of the mountains right in front of them. He then refers to the map and shows them that they are surrounded on all sides by mountains so they will have to traverse through them to get to Fuchsia City.

Team Rocket has stopped for lunch as Meowth decides to work out instead of eating his lunch. Just as they start to eat, a large explosion is heard in the distance which also shakes the ground. Team Rocket find that instead of eating their lunch, it is covered all over their body. Jessie and James are extremely mad that their lunch was spoiled and take off to find who was responsible.

Ash and his friends also hear the explosion and run down the path to see what was causing it. They soon come upon a convoy of trucks heading up a road towards a building that is under construction. Jessie and James also discover the construction site and they see that there is rock blasting. Moments later the road gives way and a bunch of trucks get into an accident.

Pikachu can hear something under the ground and a Diglett appears in front of Pikachu. Meowth sees the Diglett and Pikachu on the road. Ash, Misty and Brock run up to a construction worker that got out of his truck that was in the accident to see if he is alright. He exclaims that the Diglett are destroying everything. He points to the Diglett group that has appeared down the road. Misty calls them cute but the construction worker is quick to tell her that thanks to them, they can't finish building the dam.

Ash gets out his Pokedex to look up Diglett. The dex explains that the movement of the ground Pokémon Diglett can be easily detected by their tracks of upturned earth. Ash looks at the road and doesn't see any upturned dirt so he is a bit confused. The construction worker explains that they can't get supplies through because of Diglett wrecking the road and that they have created a special division for developing strategies to fight off the Diglett but has proved unsuccessful.

The construction worker then tells Ash and his friends that they are calling for any able Pokémon trainer who is traveling through the area that is willing to help them get rid of the Diglett will receive a reward of a 6-night, 7-day stay at the famous Giva Hot Springs Resort. Just as he finishes explaining that, Gary appears in his car with fanclub of girls.

Gary insults Ash for a bit before the construction worker had enough of their fooling around and tells them to get back to the business at hand of getting rid of the Diglett's. Gary is quick to tell him that he's on the job now and he won't have to worry about them for much longer. Jessie and James overhear the Construction Worker's rant that there would be a reward for those that got rid of the Diglett and they decide that they could use a little relaxation at the hot spring resort.

The Construction Worker holds a group meeting at the construction site stating that he greatly appreciate all the talented Pokémon trainers that have shown up to help them get rid of the Diglett. Team Rocket realize that there is a lot of trainers there and they have a lot of Pokémon. James gets out a calculator to figure out just how many Pokémon they would have but stops when he realizes they couldn't possibly defeat all those Pokémon with just Ekans and Koffing. Team Rocket realizes they need an alternate plan instead.

The Construction Worker continues his meeting telling the Pokémon trainers that greatest parasitic bug Pokémon of the century is Diglett. Gary quickly corrects him by saying that the term mole Pokémon would be more appropriate. Ash gets a bit mad at Gary for showing off. Suddenly the Diglett appear and wreck a parked bus.

Gary tries to send out his Pokémon but just as its about to appear, the Pokéball closes and it doesn't come out. A Diglett appears and brings the Pokéball back to Gary. Gary tries throwing another Pokéball to release his Pokémon but like the first time, it doesn't come out. All the Pokémon trainers throw their Pokéball's trying to see if their Pokémon would come out but none do. A pile of Pokéball's is now in front of all the trainers and the Diglett's reappear and return all the Pokéball's to their trainers.

Ash tries to send out his Squirtle but Pikachu quickly tries to stop him from doing so but it still gets thrown but Squirtle doesn't come out. Gary realizes that the Pokémon don't want to battle the Diglett for some reason which Pikachu confirms. The Construction worker is then seen playing 'Wack-a-Diglett' with a hammer with little success. Gary then comments to Ash that wacking them with a hammer won't work because Diglett can pull their heads in at 186,000,282 miles per second, the speed of light. Gary then decides that it was best for him to just continue his journey to become a Pokémon Master and drives off.

Night arrives and Ash, Misty and Brock rest in a hot spring nearby as they discuss why the Pokémon wouldn't come out of their Pokéballs. The Diglett appear at the hot spring and Ash and his friends chase after them. Jessie and James meanwhile are spending their time figuring out that they need to get a certain degree of experience points before they can successfully evolve their Ekans and Koffing. They begin to cry and their Pokémon begin to evolve.

Ash and his friends find out why the Diglett were attacking the contruction site. The area is the Diglett and Dugtrio's home and they work and live in the mountain range. They realize that if the dam is completed, the whole forest would be completely covered with water and nothing could live there. The construction worker cancels the dam building project just as Team Rocket appears. They reveal that Jessie's Ekans evolved into an Arbok and that James's Koffing evolved into a Weezing. They attack but are quickly stopped by Ash and friends. Now that the Diglett and Dugtrio situation is resolved, Ash and his friends continue their journey to Fuchsia City.

English Official Summary

Ash, Brock, Misty and Pikachu are lost deep in the mountains. As they press forward on a rough road not even shown on their map, they suddenly hear a large explosion. Running toward the sound in surprise, the party emerges on a construction site where tractors are building a tremendous dam. Ash learns that the foreman is trying to recruit skilled Pokémon trainers because earth Pokémon, Diglett, are interfering with construction and delaying the completion of his work. The foreman has been recruiting Pokémon trainers to get rid of the Diglett. He will award free passes for travel to a luxurious natural hot springs to anyone who can accomplish this. As Ash scopes out the recruits, he notices a familiar enemy in the mix, Gary.

French Official Summary

Sacha, Pierre, Ondine et Pikachu sont perdus au fond des montagnes. Alors qu'ils suivent une route accidentée qui ne figure même pas sur leur carte, ils entendent soudain une violente explosion.

German Official Summary

Ash, Rocko, Misty und Pikachu verirren sich in den Bergen. Auf ihrem Weg über eine nicht verzeichnete Straße hören sie plötzlich eine gewaltige Explosion.

Italian Official Summary

Ash, Brock, Misty e Pikachu si sono persi in montagna. Mentre avanzano su un difficile sentiero non riportato sulla loro mappa, improvvisamente odono un'assordante esplosione...

Portuguese Official Summary

Ash, Brock, Misty e Pikachu se perdem nas montanhas. Enquanto eles tentam passar por uma fissura que não aparece em seus mapas, eles repentinamente ouvem uma grande explosão!

Finnish Official Summary

Ash, Brock, Misty ja Pikachu ovat eksyneet vuoristoon. He kulkevat vaikeaa polkua, jota ei löydy kartalta, ja kuulevat yhtäkkiä räjähdyksen!

Spanish Latin America Official Summary

Ash, Brock, Misty y Pikachu se encuentran muy perdidos en las montañas. Mientras se apresuran por un camino irregular que no aparece en su mapa, ¡de repente oyen una gran explosión!

Spanish Official Summary

Ash, Brock, Misty y Pikachu están perdidos en las montañas. Cuando avanzan por una escabrosa carretera, que ni siquiera aparece en su mapa, escuchan de repente una gran explosión.

English Great Britain Official Summary

Ash, Brock, Misty and Pikachu are lost deep in the mountains. As they press forward on a rough road not even shown on their map, they suddenly hear a large explosion. Running toward the sound in surprise, the party emerges on a construction site where tractors are building a tremendous dam. Ash learns that the foreman is trying to recruit skilled Pokémon trainers because earth Pokémon, Diglett, are interfering with construction and delaying the completion of his work. The foreman has been recruiting Pokémon trainers to get rid of the Diglett. He will award free passes for travel to a luxurious natural hot springs to anyone who can accomplish this. As Ash scopes out the recruits, he notices a familiar enemy in the mix, Gary.

Dutch Official Summary

Ash, Brock, Misty en Pikachu zijn hoog in de bergen verdwaald. Wanneer ze verder gaan over een moeilijk begaanbaar pad dat niet op de kaart staat, horen zij plotseling een harde explosie!

Norwegian Official Summary

Ash, Brock, Misty, og Pikachu går seg vill på fjellet. I det de prøver å komme seg gjennom ulent terreng på en vei som ikke står på kartet, hører de plutselig en stor eksplosjon!

Swedish Official Summary

Ash, Brock och Misty är vilse långt inne bland bergen. När de kämpar sig fram längs en svårframkomlig stig som inte finns med på deras karta, hör de plötsligt en kraftig explosion!

Danish Official Summary

Ash, Brock, Misty og Pikachu er faret vild i bjergene. Da de maser sig gennem et barsk terræn, som ikke er på kortet, hører de pludselig en kæmpe eksplosion!