Ash and his friends have reached the base of Mt. Silver and are nearing the Silver Conference, so they stop at a Pokémon Center to rest. The group also decides to call Professor Elm. The Professor admires how well Larvitar is developing, making a point of its gain in self-confidence. Elm gives Ash instructions as to what to do when the group reaches the top of the mountain, right before ending the call. Just then, a Trainer approaches them and makes the assumption that the group is on their way to the Silver Conference. The boy wastes no time in challenging Ash to a battle.
Just outside of the Center, the boy introduces himself as Satchel. Ash and Satchel take their places at opposite ends of a battlefield. Satchel sends out his Magby, prompting Ash to consult his Pokédex. Having learned that Magby is a Fire-type, Ash decides to send out Cyndaquil. Misty is surprised by his choice in Pokémon, wondering why Ash didn't choose his Totodile to battle Magby. On the other hand, Satchel commends Ash in his "fighting Fire with Fire" strategy. Brock, acting as referee, signals the start of the battle. Cyndaquil dodges Magby's Flamethrower, and counters with a Quick Attack; Satchel is impressed. Ash tells Cyndaquil to use a Swift attack, and then its own Flamethrower. Satchel orders Magby to use its Flamethrower once more and the two Pokémon's attacks meet, resulting in an ascending cascade of fire. Magby's move eventually prevails, but Cyndaquil manages to jump out of the way before it is damaged. Ash has his Pokémon use Tackle, and Satchel responds by ordering Magby to use Double Team. Cyndaquil stops in its tracks as Magby's copies surround it, and begin running in a circle. Taking a chance, Ash orders Cyndaquil to go after one of the Magby; Cyndaquil attacks a fake, and Magby's Double Team is disrupted. Appearing from behind Cyndaquil, Magby is told to use its Dynamic Punch. The attack strikes Cyndaquil dead-center; Cyndaquil is unable to battle, and Satchel is declared the victor.
After the battle, Ash decides that his Cyndaquil is in need of a long rest. Satchel approaches Ash and commends him on his training of Cyndaquil, its speed, and the battling as a whole. Ash shows similar praise for Magby and its range of attacks. Although happy, Satchel expresses his goal to get his Magby to evolve into a Magmar. As a fellow Trainer on his way to the Silver Conference, Satchel states that, as a Magby, his Pokémon won't be strong enough to compete against the stronger Pokémon that they will surely face. Satchel feels sure that the battle that Ash and he just had will aid a lot on Magby's way to evolution.
A little while later, Ash, Pikachu and Cyndaquil are seen poolside, Cyndaquil recuperating from its battle. Ash seems worried about the upcoming Silver Conference. While he knows that Cyndaquil has "awesome" strengths, he divulges the same worry that Satchel had earlier regarding his unevolved Pokémon. All of a sudden, Ash spots an unknown Trainer training with his Quilava, the evolved form of Cyndaquil. Seeing this, Ash conjures the determination from within him to get his Pokémon to evolve. Returning to the group, Ash announces that it's time for some "special training", and herds all of his Pokémon before heading to a field. All of Ash's Pokémon are paired with a training partner to battle with: Noctowl with Pikachu, Totodile against Cyndaquil, and Phanpy is paired up with Bayleef.
Off in the distance, Team Rocket can be seen from behind some bushes in a wooded area. Jessie spots multiple Trainers, most with evolved Pokémon, training in the field. The trio decides then that they are going to steal all of the Pokémon belonging to the Pokémon Trainers, along with Pikachu.
Brock and Misty, having been distracted by Ash's training, notice that Larvitar has wandered off. Having made its way to the field in which the other Trainers are training, Larvitar is startled by a Voltorb; the Trainers take notice of the seemingly rare Pokémon. Brock and Misty come to Larvitar's rescue just before any of the Trainers decide they want to make a newly caught Pokémon out of it. Just then, a sudden gust of wind drags all of the Pokémon through the field. Ash soon takes notice of the ordeal and runs to save Larvitar. He is, however, soon swept up by the wind as well; Bayleef grabs onto Ash with her Vine Whip. Just as Ash is pondering what could be causing the wind, Team Rocket appears in their Meowth balloon and recites a variation of their motto. It is revealed that a mecha attached to the balloon is being used to suck all of the Trainers' Pokémon up, including Satchel's Magby; Ash's Pokémon are left on the ground. Ash orders Cyndaquil to use its Flamethrower on Team Rocket, but Meowth has it sucked into the machine before it gets a chance to attack. Ash is also vacuumed up with Larvitar in hand, but Ash gets stuck in the nozzle. Larvitar manages to land on top of the machine without getting sucked inside. Heading off into the distance, Team Rocket, Ash, and all of the Pokémon, are followed on foot by Brock, Misty, Satchel, and Ash's other Pokémon.
Team Rocket lands at a nearby wood cabin and lowers the stolen Pokémon into a truck. Jessie has also tied Ash up and left him locked up within the cabin. Outside, Team Rocket is admiring the load of Pokémon they have stolen. They express their pride in their plan of using a truck to haul the Pokémon away, thinking no one would ever catch them. Moving to the front of the truck, Larvitar approaches the vehicle and Bites down on a rear tire. To the surprise of Team Rocket, the truck leans drastically; Larvitar quickly Digs underground. Ash, wondering what's going on outside the cabin and is surprised to see Larvitar appear from beneath the floorboards. Using its Bite, Larvitar frees Ash from his rope constraints. Ash is both very happy to have been saved by Larvitar and angry that it would put itself in so much danger. Just then, Brock, Misty, and Satchel are shown to not have found anything; their hopes now lie in Noctowl's wings.
Team Rocket is flabbergasted as to why the tire was flattened; Jessie promptly tells James and Meowth to fix it. Sneaking up from behind the cabin, Ash tells Larvitar to have Cyndaquil and Magby use Flamethrower to melt the glass blocking their escape from the machine. Larvitar agrees and digs underground, moving towards the vehicle until it is just behind it. Larvitar jumps up into the truck and conveys Ash's message to the Fire types. Magby and Cyndaquil begin their attempt at escape. Having finished changing the tire, Team Rocket loads back into the truck cabin and is ready to leave. To prevent this, Larvitar bites down on the exact tire that had just been changed, inhibiting their vehicle once again. As Jessie "supervises" the changing of tires once again, Noctowl spots Team Rocket during its aerial search. Alerted by the Flying-type, Brock, Misty, and Satchel head on their way to save Ash and the stolen Pokémon from Team Rocket.
With help on the way, the Fire duo of Cyndaquil and Magby has melted a hole in their cage; the stolen Pokémon then escape. Having heard the commotion in the back of the truck, Team Rocket goes to investigate. Ash tells Larvitar from behind the cabin that the Pokémon have to hide. To Team Rocket's surprise, there is a hole in their machine and all of the Pokémon are nowhere to be found. As Jessie inspects the machine, Cyndaquil and Magby pop out and greet her with a Flamethrower attack to her face. Ash runs out from behind the cabin and orders the Pokémon to flee from the truck. With all of the stolen Pokémon on his side, Ash tells Team Rocket that he is leaving and taking all of the Pokémon with him. Jessie doesn't like this and sends out her Arbok; James then proceeds to send out his Weezing. Arbok's Bite attack, and Weezing's Tackle attack, are then ordered by their Trainers. All of a sudden, Noctowl swoops down and strikes the two Poison-type Pokémon. Soon enough Brock, Misty, Satchel, and the rest of Ash's Pokémon arrive in tow. A Poison Sting attack from Arbok, as well as a Sludge attack from Weezing, is successfully countered by a Flamethrower from Magby. Ash then orders Phanpy to Tackle Arbok and Weezing into Team Rocket, and then Totodile uses its Water Gun on the group. Jessie retaliates by swinging Arbok by its tail, essentially using a "fling attack". Satchel has his Magby hit Arbok away with a Dynamic Punch. Reeling from its successful attack, Magby begins to evolve, much to everyone’s surprise. Unwilling to give up, Team Rocket sends their Pokémon to attack once more. Arbok's Take Down is no match for Magmar's powerful Flamethrower. Ash orders Cyndaquil to finish them off with its own Flamethrower, causing an explosion that blasts Team Rocket off into the distance. Satchel thanks Ash for his efforts, though Ash admits that Larvitar deserves all of the credit.
Later, all of the stolen Pokémon are reunited with their owners. As Ash and company are readying to head off, the group and Satchel part ways. Misty proclaims that Ash has found a new rival in Satchel. Despite Brock's claims of struggle Ash will probably face in the Silver Conference if facing Satchel, Ash shows the confidence that he can beat anyone that comes his way. He has realized that even though his Pokémon haven't evolved, they have the power and heart to win if he uses their power in the right ways. The group heads on their way to the peaks of Mt. Silver.