As our heroes once again make their way through a seemingly secluded forest, Ash collapses and tells Misty and Brock that he has a stomachache. Misty comments that Ash shouldn't have had those four hamburgers for lunch, but he corrects her, saying he had five. Misty asks Brock whether he has any medicine, and he reports that he ran out. Stuck and out of ideas, the gang suddenly hears a voice offering for help. Misty and Brock turn around to see who it is, but finds no one. They look down, and see a very short old man, who Brock accuses of being an evil nasty troll. The old man, who calls himself Old Man Shuckle, yells back, saying that he only wanted help, but begins to walk away since he's just "evil and disgusting". Brock tries to apologize, calling him "Old Man Chuckle". He yells back once again as Misty pleads for his assistance. Old Man Shuckle walks over to Ash and gives him several small pills, which he swallows. Ash begins to feel better, when a giant pink cloud erupts from his mouth, knocking him out. Misty approaches Old Man Shuckle as he tells her that the medicine is the same thing he gives to his Pokémon. She begins to grow angry since her friend was given Pokémon Medicine, but Ash unexpectedly wakes up with his stomachache all gone. Old Man Shuckle walks over to Ash and mentions that the medicine he makes work for both Pokémon and humans. Brock, now knowing that Old Man Shuckle made the medicine himself, calls him a great man, like a wizard surrounded by a magical light. Misty notices that the light is just a flashlight. Old Man Shuckle invites our heroes to where he makes his medicine, and Brock enthusiastically accepts.
Inside a small shack, Old Man Shuckle shows the gang where he mixes his all-natural ingredients to make his Pokémon Elixirs. Brock, dying to know Old Man Shuckle's secret, begs for him to tell him. Old Man Shuckle agrees, and takes them to another small cabin, where our heroes find dozens of what seems like "hard-shelled pods" sitting in shelves. Misty picks one up, when an arm comes from the shell and touches her. She drops it, and the Pokémon, Shuckle, comes out. Ash uses Dexter to find out some more information, who tells that Shuckle have the ability to turn whatever items are placed in its shell to a unique juice. Old Man Shuckle explains that he puts all of his natural ingredients inside the Shuckle shell, and when the time comes, a powerful elixir, capable of increasing a Pokémon's muscle size, boosting their attack power, or performing many other properties, comes out. With different Shuckle, he can make various types of medicines, such as a juice from a purple Shuckle that allows the taker to tame any and all Pokémon. Fascinated by this idea, Brock begins to dream of how powerful a breeder he can be if he takes it, and asks Old Man Shuckle for some of the juice. However, Old Man Shuckle mentions that a purple Shuckle are very rare, but supposes that if he finds one, he can spare some of its juice. Old Man Shuckle then calls for his Bellsprout, Spoopie.
Outside, Old Man Shuckle explains that Spoopie can sniff out the Shuckle's locations, and tell which ones are done making juice. Unfortunately, at his old age, it gets harder to catch the Shuckle. Ash asks why he can't just capture the Shuckle, and Old Man Shuckle replies that only wild Shuckle produce potions enough powerful to use. Therefore, he returns a bunch of Shuckle to his shack where he inserts the ingredients, returns to the mountain, places the Shuckle back, waits one year, and then finds which ones are ready. However, even with Spoopie, finding the Shuckle are very difficult, which is why he asked for the gang's assistance in return for Brock's juice. They accept to the terms, and begin the search.
Eavesdropping on the group nearby, Team Rocket decides to find the purple Shuckle before our heroes do, and with its juice, they can become the most powerful Pokémon Masters.
Spoopie begins sniffing the area, and finds something of interest. It speeds away at an amazing speed, and with their carts, Ash, Misty, and Brock give chase. Arriving at its destination, Spoopie begins to lift up heavy rocks in which the Shuckle are under using Vine Whip. Spoopie finally finds a group of juice-ready Shuckle, and begins to wildly toss all of the Pokémon into the air. The gang tries their best to catch the Shuckle, but there are too many. Brock tells Spoopie that he's a breeder, not an outfielder as Pikachu, trying to stop Spoopie, gets smacked with a Shuckle itself. Spoopie then hurries off again, and Brock follows, leaving Ash and Misty behind. However, going too fast downhill, he trips and slams into a tree. Ash and Misty catch up with Brock, finding him shaken from the crash landing.
Meanwhile, Spoopie unearths a rock and finds the purple Shuckle. The gang approaches the two conversing, when suddenly Team Rocket makes their appearance from a nearby tree. Jessie grabs the purple Shuckle as James uses Weezing's Smokescreen as a cover-up for their escape. When the smoke clears, Team Rocket is nowhere to be seen. However, Spoopie picks up the scent, and takes off.
Exhausted from running, Team Rocket stops for a water break. Unfortunately, Meowth tells that he turned their water bottle in for the deposit. Jessie and James come up with the idea of trying the Shuckle juice and forces Meowth to be the first to taste. Meowth's reluctance changes when he swallows some of the delicious juice. Jessie and James give it a try, and the two are pleased.
Coming across a river, Spoopie stops and begins to act strangely. Suddenly, dozens of Shuckle emerge from the rocks and trees and begin to walk in the same direction. Old Man Shuckle appears from nowhere, and tells the gang that there could only be one reason for this: the thieves who stole the purple Shuckle are drinking its juice. He tells our heroes that the Shuckle will lead them straight to Team Rocket.
Jessie and James find a calm and tranquil state with their warm and fuzzy feeling. Meowth, with little hearts in his eyes, begins to coddle James with affection. He backs away from the dazed Pokémon, and screams can be heard throughout the forest.
Still following the Shuckle, Old Man Shuckle explains that drinking the purple Shuckle juice in its undiluted form emits a powerful pheromone that attracts all Pokémon lovingly for three days and three nights. Brock realizes that Team Rocket might be in for some serious trouble, and the group continues.
Meowth begins to tackle James and licks him uncontrollably. Jessie then finds a Shuckle attached to her arm doing the same thing. Suddenly, Team Rocket discovers dozens of Shuckle looking at them with fondness.
Seeing Team Rocket run away from the Shuckle, Brock explains to them the cause of the strange yearning. Misty orders for them to return the purple Shuckle, and Jessie sends out both Arbok and Wobbuffet to attack. However, her Pokémon prove to be affected by the pheromone, and begin to love and hug its trainer. James calls out Victreebel to stop them, but like always, the Pokémon tries to eat him alive instead. Team Rocket recalls all of their Pokémon, and lets Pikachu finish them off. Just as Ash commands it to use Thunderbolt, Pikachu stops and begins to embrace Jessie. Old Man Shuckle decides that the madness has gone too far, and throws some powder into the air. He explains that the powder neutralizes the effect of the pheromone, and returns the Pokémon back to normal. As Jessie prepares to leave with Shuckle and Pikachu, the purple Shuckle licks her in the belly and she throws it into the air. Spoopie comes and uses Vine Whip to catch the purple Shuckle. Still having Pikachu, Team Rocket is about to make their escape, when they discover Pikachu's back to normal as well. They try to run from its imminent electric attack, but they're hit, and sent blasting off once more.
Back in the shack, Old Man Shuckle presents Brock with the taming medicine he was promised. Brock thanks him, but refuses to accept the elixir. He tells that he doesn't want Pokémon to listen to him because of some chemical reaction, and he would rather become the world's best breeder the legit and fair way.
As the gang depart from Old Man Shuckle and Spoopie, Team Rocket finds themselves in a jam; surrounded by a group of obsessed Beedrill and Ursaring, which are bound to attack when the juice wears off. Better luck next time!