Ash, Misty, and Brock have made it to Celadon City and Brock, Misty immediately smell something. Brock dashes off in the direction of where it is. Ash follows him, and finds him with his face pressed up against a pane of glass. He looks in, and sees three girls leaning against a counter. Ash tells him that he'll be leaving with Misty and Pikachu, but can't find them. Brock points inside, and Ash sees them talking to the girls about perfume. Ash enters, and tells Misty not to buy any perfume, as he thinks it's a waste of money. The manager walks in, and scolds him for saying such things. Ash defends himself, saying that perfume only turns guys to zombies. He pulls Brock inside as an example. The manager is angered, and kicks Ash out of the store, literally. Ash decides to head to the gym.
At the gym, however, he is not permitted entrance because of what he said about perfume, saying that they manufacture it in the gym. They stamp an "X" on his face, and shut the door. Ash desperately tries to get them to let him in, but they don't let him. Elsewhere outside the building, Team Rocket breaks in through a window. They review their plan to steal the perfume and sell the formula for lots of money. They enter the building and search for the perfume. Jessie uncovers a Gloom, and James accidentally wakes him up. James sends out Koffing to attack him, but he easily defeats him with a burst of really smelly gas. Meowth complains about how bad it smells, and Jessie reminds him that he doesn't have a nose. One of the girls knocks them out, and stamps "X”s on their faces. She then hangs all three of them up in a tree.
Ash approaches them as they hang there, and James asks him to let them down. Jessie scolds him for being a traitor, but gets an idea. She asks Ash if he was able to get into the gym, and tells him that if they untie them, they'll help him get inside. Ash is hesitant at first, but agrees. Later, at a department store, Team Rocket has dressed Ash up as a girl. Team Rocket reminds him to keep his voice high, and they go to the gym building. Upon reaching it, they go inside and Team Rocket, also in disguise, tells the receptionist that Ashley wants to apply to the gym. Ash asks the girl there where Erika is, and she tells him that he'll see her shortly. Team Rocket dashes off, casting off their outfits. Meowth jumps out of James's shirt with a bomb in his paw, and James asks Jessie what it is for. She tells him that it is for revenge for stamping the "X" on her face. They continue to dash down the hall.
The girl at the receptionist desk leads Ash to a group of people listening to a story being told. He notices Misty and Brock in the crowd and instantly gets worried. The girl who was reading the story, Erika, stands up to welcome the new arrival, and Ash immediately recognizes her as the manager of the perfume shop. Brock approaches Ash and welcomes him as well. It's at this time that Ash notices Pikachu, and he starts to get really worried. Misty asks Erika why Gloom doesn't smell bad, as they usually do, and she explains that Gloom only smell bad when they are threatened. She then explains that, a long time ago, Gloom saved her from a Grimer and they've been friends ever since. Misty notes how she wishes Ash had heard the story, and he absent-mindedly tells her that he did. He catches himself, and asks them not to stare at her. Misty suspiciously tells him that he looks familiar, and Pikachu walks over. Pikachu recognizes Ash immediately, and hugs him. Ash tries to get Pikachu not to blow his cover, but is shocked. His wig falls off, and Brock shouts out his name. Ash tells Erika that he wore the disguise to sneak into the gym so he could battle for a badge and challenges her.
Meanwhile, Jessie and James have found the perfume they were looking for, and take it, planning on discovering its formula. Back at the arena, Erika accepts Ash's challenge, telling him to use three Pokémon. Ash sends out Bulbasaur, and Erika uses Tangela. Bulbasaur uses Vine Whip, but Tangela spins, pulling him closer. Tangela then uses Stun Spore, putting Bulbasaur out of commission. Ash thinks about sending out Primeape, but remembers what happened before. He decides against it and sends out Charmander and Erika sends out Weepinbell, who uses Razor Leaf. Charmander's Flamethrower burns the leaves up, and he finishes Weepinbell off with a Skull Bash. The people in the stands note how well Ash is doing, and Erika sends out Gloom, who defeats Charmander with a burst of smelly powder. Ash thinks about who to send out next, and Pikachu offers his services. Suddenly, a voice comes from the ceiling and they all look up to see Team Rocket. They jump down, and Meowth sets off the bomb, which happens to be right under them. Team Rocket is thrown through the roof, but they still have the perfume.
The bomb has set a fire ablaze inside the gym, and everyone hurries to gather up the Pokémon to get them out. Once outside, everyone works at putting out the fire. Ash and Misty send out Squirtle, Staryu, and Starmie, who also help out. Brock tells Geodude to throw dirt on the flames. Erika rushes up and tells them that Gloom is still inside. Ash dashes inside to find him. He quickly searches the gym, and finds Gloom cowering in a corner. Ash starts to get close to him, but he lets off a burst of smelly powder. The ceiling starts to cave in, and Ash takes a deep breath, then runs inside. He approaches Gloom, but is forced to take a breath. He realizes that the air doesn't smell, and is happy to know that Gloom trusts him. He scoops Gloom up, and runs outside.
The next morning, Erika thanks Ash for saving Gloom and helping with the fire. To show her gratitude, she gives him a Rainbow Badge. Brock and Misty congratulate him, and Ash asks Erika about Team Rocket. Erika laughs, and tells Ash that the vial they stole had only one of the ingredients: Gloom's "special scent." Ash walks off holding the badge high. We've all learned an important lesson here: You can't judge a Pokémon by its smell.