Ash, Misty, and Brock are sitting by a lake with Pikachu, Psyduck, and Vulpix. Psyduck starts drinking the lake water and Misty tells it that the cold water will only make its headache worse. Brock says Vulpix's fur is beautiful thanks to Suzy. This annoys Misty and she asks Brock if he would like to trade Psyduck for Vulpix. Brock refuses. They all head to the gym and a Venonat watches them from the nearby trees.
Ash and his friends continue walking and they come across an odd looking mansion where they ask for directions to the gym. They are directed to an old house. They open the front door and they enter and empty hallway. Misty leans up aganist a wall and she falls through it. Ash and Brock search along the wall and they open up the wall and they find Misty. They also find the same Venonat that was spying on them before. It runs away and Ash and his friends decide to follow it.
The Venonat runs around a corner and when they run after it, Ash hits his head on an invisible wall. They turn around and decide to leave, when they walk into another wall. Ash falls through the side of the house and he hangs on to the side of it. Misty and Brock manage to pull him up. Ash goes through a door and yells for Misty and Brock to help him. They run through the door and they find themselves in an empty room.
They start calling out for Ash and the door closes behind them and it revals Ash, stuck to the wall. A girl drops down through the ceiling and says her name is Aya. Aya says they can't leave until she and Ash have a battle. Ash agrees and after She helps Ash get down from the wall, Aya sends out Venonat. Ash sends out Bulbasaur. Bulbasaur uses Tackle but Venonat avoids it. Venonat uses Stun Spore but Bulbasaur deflects it by using Whirlwind and then uses Leech Seed. Aya recalls Venonat. Ash is happy until a Voltorb appears and selfdestructs. Koga appears and explains that they are at the Fuchsia City Gym and that he is the gym leader. He also says that Aya is his sister, that he will battle Ash, and that they can't leave until he and Ash have a battle.
Ash agrees and sends out Pidgeotto. Koga sends out his own Venonat. Since he just beat Aya's Venonat, Ash is sure he will win. Koga warns him that his Venonat is very strong. To prove his point, Venonat then evolves into Venomoth. Koga tells Venomoth to use Stun Spore. As he did before, Ash uses Whirlwind. But Stun Spore succeeds and Venomoth uses Sleep Powder. Ash recalls Pidgeotto and sends out Charmander. Venomoth uses Stun Spore again, but Charmander blocks it with Flamethrower.
Team Rocket then breaks into the gym. Koga, Aya, and Ash use their Pokémon to attack Team Rocket, but James throws a sticky substance at them, sticking them to the floor. Pikachu steps up to fight, but Jessie throws the substance at Pikachu also, sticking him to the floor.
Misty tries to send out Starmie, but Psyduck comes out instead. She tells Psyduck to use Tail Whip, but it does nothing. Psyduck then uses Scratch on Arbok. This doesn't work and Arbok starts biting Psyduck's head, making its headache worse. Koga then uses some Voltorb as smoke cover for their escape. Ash and friends then notice something about the new room they're in: everything is slanted.
They try to get the stuff off but it was no use. Team Rocket then appears and notice the room is slanted too. Psyduck then runs around like a maniac. Misty tries to recall it but misses every opportunity, annoying her. Meowth also becomes annoyed and kicks Psyduck out of the way. James tries to grab it but Meowth says they don't need it. Misty then felt sorry for it and comforted it. To the surprise of everyone, Psyduck starts using Psychic type moves on Team Rocket. The attacks, blast them off and remove the sticky substance from all the Pokémon. Koga and Aya offer to trade for Psyduck but Misty says she would't trade Psyduck for anything.
Ash and Koga continue their battle outside. Ash choses Charmander and Koga choses Golbat. Charmander defeats Golbat by using Ember and Fire Spin. Koga gives Ash the Soul Badge and Ash and his friends head off for the next gym.
- Ash tells Bulbasaur to use Whirlwind, though a Bulbasaur can't learn it in the games.
- Koga has Venomoth attack Pidgeotto by using Stun Spore and Sleep Powder but in the games, a Pokémon can't be affected by more than one status ailment at a time.
- This is the first of many episodes where Maddie Blaustein was the voice of Meowth until season 9 when she passed it on to Jimmy Zoppi.
- Brock's eyes are open after he is hit by Charmander's Flamethrower.
- This episode has the first time Psyduck comes out of its Poké Ball when Misty is calling out a different Pokémon.
- This episode was banned in South Korea.
- The "Who's that Pokémon?" in this episode is Venonat.
- Ash sees Venonat.
Ash: "That thing."
Aya: "This Venonat told me that three stupid looking people entered the building."
Venonat: "Venonat. Veno."
Ash: "For your information, we're not the stupid ones! I accept your challenge! Hm. But first, could you let me down?"
Everyone falls over.
Watch this and other episodes: Pokémon Episode 32: The Ninja Poké-Showdown