The episode picks up right after the previous one with Paul challenging Candice to a Gym battle, but Candice tells Paul that her Pokémon need to rest after the battle against Ash and would like to reschedule for tomorrow. As Paul agrees and begins to leave, Ash shows off the Icicle 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 learns that Paul was Chimchar's original Trainer and how Ash and Paul contrast so much. Dawn notices that Ash is missing as outside Paul's Magmar and Electabuzz train, Magmar firing Flamethrower at Electabuzz and towards the sky. Ash meets up with Paul and mentions how Grotle perfected the defense strategy Paul's Torterra taught it and wanting to thank Torterra, but Paul recalls his Pokémon and heads inside, criticizing Ash for using a Grass-type Pokémon against an Ice-type Gym Leader. Before he can get inside, Zoey confronts him, but Dawn holds her back. Paul heads inside without another word as Zoey hopes that Candice wipes him out in the battle.
The next day, Reggie drives by in a van when he notices Paul outside the Center. He pulls over and greets his brother. Inside, Ash and his friends notice Reggie as Dawn fills Zoey in. They head outside and greet Reggie, who mentions that he just dropped off a Pokémon he was caring for. Ash mentions that he won at the Snowpoint Gym. Reggie congratulates him and asks Paul if he can watch the match, which Paul allows. Zoey notices how Paul contrasts 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 I 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 as an SUV pulls up. Candice introduces herself to Brandon and expresses her admiration of the Battle Pyramid. Brandon introduces the woman getting out of the SUV as 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 turns it down, 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 a Rock-type like 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. Brock shows some surprise at how strong Regirock was after being hit with the Arm Thrusts. 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 summons 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 before following up with Hyper Beam. Electabuzz is blasted by the attack and taken out. Ash notes he can't believe how Brandon was able to easily defeat Paul's Electabuzz. Paul recalls his Electabuzz and at the same time Brandon recalls his Regirock, 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 Registeel takes it without much falter which surprises everyone. 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. After Dawn checks Nidoking, she states Nidoking is a Poison-type, but notes Poison-type moves don't work on Steel types. Zoey states that is true, but Nidoking is also a Ground-type whose moves are effective against Steel types. They will just have to wait and see what kind of move Paul will use. 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 mocks 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 represents 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. 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 knows that Paul has already lost the match. Regirock easily endures Magmar's Flamethrower before using a Shock Wave to knock out Magmar, therefore giving Brandon a perfect victory over Paul. Ash feels bad for Paul, who is left shocked and upset at being totally defeated in front of his brother and peers. Paul then recalls his Magmar and Brandon, recalling Regirock, then asks if the battle Paul just had was his true battle. He commends Paul on a good battle and raising and training his Pokémon very well, 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 to his elder.
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 as Candice challenges Zoey to a battle. Candice and Zoey get on Dodrio as Candice wishes Dawn good luck in her next Contest before leaving. Paul starts to leave but Reggie asks if Ash and Paul can have a Full Battle. Brandon agrees with the idea as both Ash and Paul agree to battle, Reggie setting the event at Lake Acuity in 10 days. Reggie and Paul leave in Reggie's van as Samuel and Maria arrive, telling Brandon that a situation has occurred at the temple.
- There is no Professor Oak's Pokémon lecture following this episode.
- This is the first episode starring a Frontier Brain where Scott does not appear.
- This is also the first time when a Frontier Brain appears after the Battle Frontier arc.
- This is the first episode in which both Paul and Reggie appear in person together.
- This is the second time when Paul loses a Pokémon match without his opponent losing a single one of his/her Pokémon, the first being against Cynthia 88 episodes back.
- The Sinnoh map shown on TV is similar to the one in-game.
- If the collision of Regice's Focus Punch and Ursaring's Hammer Arm isn't counted as a hit, all of Paul's Pokémon were knocked out with two hits.
- Team Rocket doesn't blast off or recite their motto in this episode.
- Regirock's Stone Edge is able to hit Electabuzz through Protect, though nothing except Feint and Shadow Force can do this under normal conditions.
- During three scenes Zoey's eyes are colored orange.
- In the Dutch dub Brandon tells Regirock to use Rock Smash (Steen Knal) instead of Stone Edge (Steen Rand).
- The Cycling Road is absent on Kanto's map.