Not long after Ash won his Icicle Badge at the Snowpoint Gym, his rival Paul challenged Gym Leader Candice to a battle! Once the match is set for the next day, Paul silently walks away. But he’s not alone for long—his big brother Reggie is in town, and once Reggie stops to talk to Paul, Ash and his friends catch up too! To top it all off, the Battle Pyramid flies right over their heads. Ash has already beaten this Kanto Battle Frontier facility, but Reggie admits he lost his own Battle Pyramid challenge.
Brandon, the Battle Pyramid King, is here to meet Maria, a maiden from the Snowpoint Temple. Paul has other ideas: he challenges Brandon to a battle, and Brandon accepts! Paul was a novice Trainer when he witnessed Reggie’s defeat at the Battle Pyramid, and it made a deep impression on him. Now he’s determined to beat Brandon in a full 6-on-6 battle and do what his brother couldn’t! Faced with Brandon’s Regirock, Paul swaps his Magmar out for Hariyama, but Regirock easily defeats Hariyama and then Electabuzz. Brandon sends in Registeel so Paul sends in Magmar, but Magmar isn’t even making a dent on Registeel. Paul switches in Nidoking instead, and Registeel scores an easy win.
Paul is quickly losing his cool; once Brandon’s Regice wipes the floor with Paul’s Lairon and then paralyzes Paul’s Ursaring, Paul gives up and lets Brandon’s Regirock knock his Ursaring out. Magmar is all Paul has left, but Regirock easily defeats Magmar too. Brandon is disappointed, but he promises they’ll battle again once Paul learns to control his emotions. As everyone files out of the Pyramid, Reggie suggests that Paul should battle Ash, and Brandon thinks it’s a good idea. The two rivals will battle in 10 days’ time—but just as that’s decided, Maria rushes up in a panic. Something terrible has happened at the Snowpoint Temple!
Just after Ash has earned the Icicle Badge, Paul arrives at the Snowpoint Gym and challenges Candice to a Gym battle. Candice tells Paul that her Pokémon need to rest and would like to reschedule for tomorrow. As Paul agrees and begins to leave, Ash shows off the his latest Badge and asks Paul how many more he has gotten, but Paul brushes him off and walks away. Dawn tells Zoey that Paul is Ash's rival while Candice notices how fierce this rivalry is compared to Dawn and Zoey.
As night falls on the Pokémon Center, Zoey is surprised to learn that Paul was Chimchar's Original Trainer, and she remarks on the difference between Ash and Paul. Dawn notices that Ash is missing, so they check outside. Ash meets up with Paul to thank him, mentioning that Grotle perfected the defense strategy Paul's Torterra taught it. Paul stops his training session and recalls his Pokémon before heading inside, criticizing Ash for using a Grass-type Pokémon against an Ice-type Gym Leader. Zoey calls Paul out on his attitude. Paul continues inside without another word as Zoey hopes that Candice wipes the floor with him in the battle.
The next day, after dropping off a Pokémon he was caring for, Reggie stops by after noticing his younger brother Paul outside the Center. Inside, Ash and his friends notice Reggie as Dawn fills Zoey in before stepping outside to greet him. Reggie asks Paul if he can watch his match against Candice, which Paul allows. Zoey notices that Paul is a complete contrast to his brother as much as to Ash. A shock wave gets everyone's attention as a huge shadow passes by, everyone looking up and spotting the Battle Pyramid. Ash identifies it, getting Reggie and Paul's attention. Paul is even more shocked at the fact that Ash conquered it and won the Brave Symbol. Team Rocket spots the Pyramid from the town while Candice watches from outside her Gym.
Inside the Pyramid control room, Samuel relays a streaming video feed from Ash at the Pokémon Center, with Brandon acknowledging their presence. As the Pyramid touches down in a clearing, Reggie drives Ash and his friends to the location. Ash and Brock tell Dawn about the Battle Frontier, how there are several facilities spread throughout Kanto and that each is run by a Frontier Brain, with Brandon as the last to defeat and the most powerful of all the Frontier Brains. Brock asks Reggie about the missing Brave Symbol he noticed at Reggie's home back in Veilstone City. Reggie confirms that the Pyramid was the only place he did not win. His usual smile drops into a serious expression, as he remarks that it was also the day he learned that he had a lot more to learn. They reach the Pyramid and meet up with Brandon. Brandon greets Reggie warmly, recognizes Brock, and even Paul, which prompts Paul to step forward and challenge Brandon to a battle. Candice arrives on a Dodrio, introducing herself to Brandon and expresses her admiration of the Battle Pyramid. As an SUV approaches, Brandon introduces Temple Maiden Maria. Brock instantly goes crazy, but Croagunk calms him. Zoey fills everyone in about the Snowpoint Temple while Team Rocket listens in, Brandon mentioning that the Temple was his reason for coming to Sinnoh. Brandon tells Samuel to go with Maria to the Temple while he battles Paul. Paul reveals his desire to defeat the person his brother couldn't, not caring whether everyone else watches or not.
Inside, Brock offers to be the referee, but Paul declines, declaring the match will be a Full Battle with substitutions allowed. Paul summons Magmar as Brandon summons Regirock. Dawn checks her Pokédex as Reggie remembers that Paul watched his battle, Regirock being the same lead Pokémon. Reggie recalls the match, he had defeated the other six Frontier Brains and defeating Brandon would allow him to become a Frontier Brain candidate. Paul has just started his Pokémon journey with Turtwig and took time out from his first journey through Sinnoh to travel to Kanto in order to watch Reggie's battle. Despite his best efforts, Brandon defeated Reggie without losing a Pokémon. Paul and his Turtwig were both shocked that Reggie lost to Brandon and was unable to defeat any of his Pokémon. Brandon harshly tells Reggie that while it was an enjoyable battle, there was nothing special or unique about Reggie's battle style, and Brandon finishes by asking Reggie where his inner strength is. Paul took these words to heart, vowing to find his inner strength with his Turtwig being just as determined as well. Brock then figures out that Paul's obsession with power is due to Reggie's loss against Brandon. Brandon states to Paul he can take on anything Paul brings because that is his battling style.
Paul immediately recalls Magmar which surprises everyone, including Brandon, since the battle just started. Brock guesses the disadvantage Magmar has against Regirock must have caused Paul to do that. Paul brings out Hariyama, which Dawn checks. The type matchup is positive for Paul as Regirock fires Stone Edge, but Hariyama blocks it easily. Paul points out that Rock-type moves won't do that much harm to Fighting types like Hariyama and asks if this is a test. Brandon smiles and states he will have to see himself. Hariyama charges forward and hits with multiple Arm Thrusts, but Regirock bear hugs Hariyama to stop the Arm Thrusts and uses Shock Wave at close range, causing it to stumble and surprising Brock in the process. Hariyama launches a Force Palm, but Regirock moves to the side and throws a Focus Punch, knocking Hariyama out. As Paul recalls Hariyama, everyone is impressed at the strength of Regirock. Outside, Team Rocket tries to decide whether to climb the pyramid again or go to the temple. Jessie and Meowth play rock paper scissors to decide, but it results in a tie.
Meanwhile, Paul calls Electabuzz. Ash predicts Paul's strategy as Electabuzz uses Brick Break to hit. Regirock fires Stone Edge, the attack is so powerful that it even manages to smash through Protect, which greatly frustrates Paul, before following up with Hyper Beam to take Electabuzz out. Ash expresses his surprise at the easy defeat of Electabuzz while Paul recalls it. Brandon recalls his Regirock as well, which benefits him on not having to deal with Regirock being immobile after firing Hyper Beam. Brandon sends out Registeel as Paul brings Magmar back out. Magmar hits with a Flamethrower, but, to everyone's amazement, Registeel takes the super-effective attack without much falter. Reggie notes that Flamethrower must have had an effect on Registeel, but it is hanging in. Registeel launches into an Iron Head and Magmar blocks it, but it flinches, negating the Will-O-Wisp order Paul gave. Paul recalls Magmar and deploys Nidoking. Dawn, after checking Nidoking, is a bit confused as to why Nidoking is up, due to Steel-type's immunity to Poison attacks. Zoey replies that Nidoking is also a Ground-type, giving it the advantage. Registeel fires Flash Cannon which hits Nidoking squarely in the face, but Nidoking uses Earth Power (Brandon showing some surprise of how Nidoking recovered), hitting before launching into Double Kick. Registeel stumbles backwards but quickly recovers, withstanding a hit from Nidoking's Thunderbolt before using Iron Head to knock it out.
Brandon begins to taunt Paul, reminding him that he wanted to defeat the man who defeated Reggie and put an end to his Pokémon journey. Paul, recalling his Nidoking, tells Brandon that the fact that Brandon defeated Reggie is the only reason why he is battling him now; all he wants is the chance to earn victory against Brandon, which his brother couldn't do. Brandon presents the ultimate challenge to all Trainers to find their inner strength and Paul knows what his inner strength is... his will. Brandon chastises Paul for this, telling him he is focusing on the past. He adds that if Paul's this obsessed with what happened to Reggie, he needs to question why he's on a journey in the first place. This clearly hits a nerve and Paul furiously brings out Lairon.
Brandon recalls Registeel and brings Regice out as Lairon uses Iron Defense. Reggie guesses Paul is trying to hang in and wait for a chance to counterstrike. Regice freezes Lairon with an Ice Beam before launching Zap Cannon, knocking out Lairon without it being able to attack (as stated by Ash). As Paul recalls Lairon, his emotions grow even more intense as he brings out Ursaring. Ursaring then launches Hammer Arm, however, Regice counters with Focus Punch and a massive backlash is created, knocking both Pokémon backwards. Ursaring prepares to use Focus Blast, but a Zap Cannon stops that attack and paralyzes Ursaring (Brock states that Zap Cannon will always paralyze a target if the attack hits). Paul gets even more frustrated and angry at this and Ash notices Paul is not trying to switch out Ursaring. Brandon then recalls Regice and brings Regirock back out, much to Paul's anger and shock. Regirock then fires Stone Edge, and Ursaring is taken out, forcing Paul to recall Ursaring. Reggie notes that Paul did not give any orders to Ursaring, having just given up on Ursaring's chances of winning. Paul brings out Magmar as his last, however with the type-disadvantage and massive difference in strength, everyone verbally states that Paul has already lost the match. Regirock easily endures Magmar's Flamethrower before knocking out Magmar with Shock Wave, therefore giving Brandon a perfect 6-0 victory over Paul. The loss leaves Paul in shock, all the while in front of his brother and peers. After recalling their Pokémon, Brandon asks if the battle Paul just had was his true battle. He commends Paul's skills, but notes that Paul let his emotions betray him during the battle. Brandon then tells Paul that they will battle again when he has learned to control his emotions. Paul silently accepts this, bowing politely.
Outside, Team Rocket is still split on deciding where to go as James notices Ash and his friends exiting. Outside, Paul still plans to challenge Candice, but in the meantime Candice decides that she and Zoey should face-off first, so they leave for the Snowpoint Gym. Paul prepares to make a move, though Reggie asks if Ash and Paul can have a Full Battle. Brandon thinks it will offer invaluable experience to both Trainers, so Reggie sets the event at Lake Acuity in ten days. The brothers then leave in Reggie's van as Samuel and Maria arrive, telling Brandon that a situation has occurred at the Snowpoint Temple.