On Mt. Coronet, Ash and Turtwig are battling Alan, an energetic Trainer with a Nosepass. The only place Nosepass can evolve into Probopass is Mt. Coronet, so Alan is eager to have all the battles he can. Sure enough, Nosepass evolves during the heated battle, but Alan's delight is short-lived: a strange device lands on Probopass's head and causes it to act strangely, even turning against Alan! It's all the work of Team Rocket and their new Probopass Power Mind Manipulator antenna, which they use to control Probopass so they can steal it and run away.
Alan is heartbroken, but Ash and his friends promise to help him rescue Probopass. They track Team Rocket to the bank of the river, and Ash sends Buizel to cross the river and steal the antenna remote control. When Buizel is spotted, a fight breaks out that damages the remote control! As Probopass runs away, so Alan leaps on its back and tries to bring it back to its senses. He even has Pikachu shock them with Thunderbolt, but nothing works.
Finally, Alan asks our heroes to knock him and Probopass into a lake, where he finally manages to pry the antenna off and restore Probopass to normal. But back on shore, Team Rocket has snared Ash and his friends in a net. When Alan, Probopass, and Buizel surface, Buizel cuts everyone free with Sonic Boom and Probopass helps our heroes defeat Team Rocket. With that done, Alan and Ash resume their battle!
Ash and Turtwig take on Alan and his Nosepass. Turtwig dodges a flurry of Zap Cannon blasts as he rushes towards his opponent before taking a sharp turn, where a chase ensues. Alan orders Nosepass to keep using Zap Cannon, and eventually, one blast hits close enough to send Turtwig flying. However, Turtwig lands on top of a rock. As Ash orders Turtwig to jump away, Alan orders it to stop, as the battle has to take place in their current location. Ash and his friends are confused by the request, but Alan explains that he wants to battle near Mt. Coronet so his Nosepass can evolve due to the special magnetic field present in the area. Ash agrees, keen to help Alan inch closer to his Sinnoh League dream.
Brock calls for the match to resume. Turtwig dodges a Rock Slide and strikes back with Tackle. Nosepass stands its ground and responds with its own Tackle. The match gets heated as Alan and Ash exchange Tackle attacks, with each taking significant damage. Nosepass suddenly becomes surrounded in a white light and promptly evolves into Probopass, which Dawn scans with her Pokédex.
Ash and Alan prepare to continue the battle when an odd helmet falls on Probopass's head. Probopass's Mini-Noses then attack Alan. A cackle of laughter alerts Alan and the others to Team Rocket, who reveal that they are controlling Probopass. Alan calls for his Pokémon to listen, though it is completely under Team Rocket's control. They have Probopass break up the ground before flying off with the Compass Pokémon. Alan is distraught by the loss, but Ash and his friends remind him not to give up.
Later, Team Rocket relaxes by a river. While Wobbuffet and James are constructing more mind-controlling helmets, Jessie is sunbathing as she daydreams of stealing more Trainer's Probopass to create an unbeatable army. Meanwhile, Brock guides the search party northbound using his compass. Suddenly, the pointer changes, indicating a sudden change in the magnetic field and hinting that they are getting closer to Probopass. Dawn and the others soon sight Team Rocket, noting all of the other helmets. Alan prepares to rush in, but Brock stops him and says that he will just be attacked. Instead, Ash sends out his Buizel, who swims across the river and gets close enough to attack Meowth and Jessie with water. Buizel, however, bungles the remote retrieval after he drops it, causing Team Rocket to notice him. In response, Wobbuffet and Buizel battle for the remote, which is then knocked into the air by Staravia. Ash jumps to catch it, but Jessie's Dustox uses Whirlwind, causing Ash to fall into the water.
The remote then falls on Probopass's antennae, causing it to explode. After it gets destroyed, Probopass continues to act out. It first attacks Team Rocket and sends them blasting off with a Zap Cannon blast, then turns on Ash and his friends. Ash has Pikachu use Thunderbolt, but this fails to destroy the helmet, only managing to make Probopass flee. Alan soon catches up and hops on Probopass to get rid of its helmet. Knowing he will also be attacked, Alan asks Pikachu to use Thunderbolt. This causes Alan and Probopass to be shocked, but the Compass Pokémon remains under the helmet's control. Alan suddenly spots a river up ahead and orders Ash use a Thunderbolt and Water Gun combo when he gives a signal. Soon, Probopass comes to a stop at a steep cliff overlooking a river, so Alan gives the signal. Pikachu's Thunderbolt, Buizel's Water Gun, and Pachirisu's added Discharge knocks Probopass and Alan into the river below. Probopass quickly sinks to the bottom, where Alan manages to pull the helmet off. With Alan still not ashore, Ash orders Buizel to dive in.
Team Rocket makes another unwanted appearance. Pikachu unleashes a Thunderbolt, but he and the group get caught up in a rocket-fired net. Alan finally manages to awaken his Probopass, and they swim back to the surface along with Buizel. Alan declares that he has his burning spirit back, though Jessie and James call on Seviper and Carnivine to teach him otherwise. Ash and his captive friends have Buizel use Sonic Boom to free themselves from the net. Team Rocket orders their Pokémon to attack, but Probopass knocks them down with Magnet Bomb. Pikachu follows up with Volt Tackle to defeat Seviper and Carnivine. Dawn's Pachirisu and Alan's Probopass then deal the finishing blow, a Discharge and Zap Cannon combination to send Team Rocket blasting off. Afterward, Ash and Alan continue their battle.