Ash's Battle Palace challenge against Spenser is about to begin, and it's going to be one big battle when the island itself is the true battleground! Ash's friends take to the skies in a hot air balloon to watch, and since no regular referee can keep up, a hovering robot called Jamero will keep everyone informed of what's going on. The first battle will be Spenser's Shiftry against Ash's Sceptile, and naturally the pair take to the forest to have their battle. Sceptile, back and better than ever after its recent romantic woes, takes a dunking during the fight but comes back to knock out Shiftry.
Next up is Spenser's Venusaur. Ash has brought Heracross in just for this match, although Heracross seems more interested in seeing if Venusaur's flower has anything tasty to eat. Speaking of tasty, after Venusaur's mighty Solarbeam defeats Heracross, Spenser takes time out of the battle for a snack break. After that refreshing pause, Swellow battles Venusaur on the beach, where the sun could prove to be an advantage for Venusaur. But the weather is unpredictable and a cloudy sky is no help for Venusaur's Solarbeam. That gives Swellow an edge that wins it the round, and now it's time for Spenser's Claydol.
Claydol is packing a powerful Hyper Beam that knocks Swellow out in short order, so now it's up to Sceptile. Things could be tough when a sudden squall blows through, but the clouds part and this time the sun is shining for Ash! The sunlight helps Sceptile charge up and its Solarbeam finishes the match, winning Ash his fifth Frontier Symbol. Next stop: the Battle Tower!
Ash, Pikachu, May, Brock, and Max stand outside of Palace Maven Spenser's battle grounds, the Battle Palace. Spenser and Scott approach Ash and his friends asking him whether he is ready, which Ash confirms. Scott and Spenser suggest that as the sun is shining, the battle be held not within the Battle Palace itself but in the jungle that is part of the grounds. Ash agrees, eager to experience a new kind of battling. Scott begins to explain the rules about the battle: it shall be three-on-three and only the challenger can substitute a Pokémon. Later, the group rides inside a Poké Ball-shaped hot-air balloon. Scott goes on to say that the battle will take place throughout the entire jungle, and it is revealed that the whole side of the island is covered in trees, with only a couple of mountains and the sea nearby.
Ash and Spenser are standing atop a battlefield on a mountain, which will act as the starting point. Scott points out this battle will test the Trainers physically as well as mentally since they will need to run around to keep with up the battle. Brock declares how Ash should be careful in his decision when choosing his Pokémon as the jungle can have a major effect on battle strategies. Brock also notes that it will be difficult for anyone to judge a battle that is constantly on the move. In response, Scott calls up a floating Poké Ball-shaped referee named Jamero. On the front, there is a camera from which the four in the balloon can watch the battle. The referee floats down to the battlefield, where Spenser and Ash are eager to get started. Ash's friends in the balloon see him on the TV screen standing ready. Meanwhile, Team Rocket are sitting in a tree, spying on Ash and Spenser with binoculars. They declare how they are going to steal Pikachu and give him to the boss.
The referee abruptly states the rules for Ash's Battle Palace match. Spenser calls out his first Pokémon, Shiftry and Ash replies with his Sceptile. The referee waves its flags and the match begins. Sceptile starts out with a blistering Bullet Seed but Shiftry is very fast and manages to dodge it. Shiftry and Sceptile run off down the side of the hill, closely followed by Ash, Pikachu and Spenser. Sceptile and Shiftry are speeding through the forest running side by side, eyes locked onto one another, Ash orders a Leaf Blade from Sceptile, but Shiftry counters it with a Quick Attack. The two continue running along the grass in the jungle as we pan out to see Brock, May, Max and Scott watching on. As Shiftry bounces through the jungle closely followed by Sceptile, Spenser compliments Ash on his Sceptile's Speed not long before he orders his Shiftry to use Double Team.
Sceptile is surrounded by many Shiftry, and before Ash can reply, a powerful Shadow Ball from Shiftry knocks Sceptile into a nearby pool. Then, as ordered by Spenser, Shiftry uses Rock Smash on the ground by the lake, which sends off a barrage of rocks from the nearby water's edge and fills the pool. Ash is worried that Sceptile has been crushed as they see Sceptile's head just duck underwater as the rocks hit the pond, along with May, Max and Brock. Ash is sure that Sceptile has been knocked out. Suddenly, Sceptile appears from atop the waterfall, jumps out and crashes a powerful Pound attack on Shiftry. This, along with a Leaf Blade, knocks Shiftry out, giving Sceptile the victory. Meanwhile, Team Rocket have just set off a tripwire, picking all four of them, Jessie, James, Meowth, and Mime Jr. up and into a net hanging from a tree.
Meanwhile, Spenser is impressed by Ash's win, but he holds nothing back for the next battle, swiftly sending out his Venusaur. Ash recalls his Sceptile and sends out Heracross, which instantly leeches onto Venusaur's flower due to its addiction to sap. Venusaur, however, flicks it off with his Vine Whip. Meanwhile, up in the balloon, Ash's friends are discussing with Scott how Heracross has the upper hand against Venusaur due to its type, but Scott knows how powerful Venusaur is and he says not to underestimate it. Ash quickly orders Heracross to attack with a Horn Attack, which Spenser tries to counter with a Razor Leaf; however, Heracross manages to knock all of the leaves out of the sky with its horn and then strike a direct hit onto Venusaur. Heracross continues to attack with Fury Attack until a powerful Vine Whip knocks Heracross back.
Heracross lands on its feet and is ready to retaliate; both Heracross and Venusaur go for a Tackle attack, meeting eyes locked in the middle. Ash orders Heracross to use Megahorn, which hits Venusaur hard, knocking it back. It slides directly into a tree knocking from it a Nanab Berry, which Spenser catches. Spenser orders a Solar Beam from Venusaur, and Ash uses the delay from the move to his advantage attacking again with a Megahorn. Meanwhile, Team Rocket have set off another tripwire, however this time they set off numerous spiked thorns and sticks which stick the trio to a nearby tree. Back to the battle, Megahorn hits directly onto Venusaur, but this time, Venusaur responds with a Solar Beam, which knocks Heracross out. Everyone is amazed at the power of the Solar Beam which came from Venusaur, especially up in the balloon.
Ash calls back his Heracross and sends out his Swellow, giving him the type advantage once more. Swellow flies down, but as Ash orders it to attack, Spenser stops the battle for a rest and a quick snack. Meanwhile, Meowth manages to set off a third tripwire. Jessie, James, Meowth, and Mime Jr. brace themselves for the trap's impact, but nothing happens. They let out a sigh of relief and take a step, only to be caught out by a camouflaged pit. This doesn't faze them, though, and they continue to try to capture Pikachu. Back to the battle, May sees Swellow flying far out into the jungle and is unsure about what Ash is up to. Brock spots the ocean and realizes where Ash is headed. Spenser and Venusaur follow Swellow. Ash orders Swellow to speed up, which Spenser tries to counter with multiple Vine Whips, but Swellow manages to avoid them. Swellow bursts out onto the beach, closely followed by Ash and Pikachu, then Spenser and his Venusaur, where the battle commences.
Venusaur uses Razor Leaf, which is only just dodged by a last-minute Double Team. Venusaur panics, unsure of which Swellow is the real one. Ash orders a Quick Attack, while Venusaur counters with a Vine Whip. The real Swellow is found, but it manages to avoid the vine and directly hit Venusaur, knocking it back. Venusaur is exhausted, which Brock points out is due to the serious damage Heracross inflicted with its Megahorn. Spenser orders a final Solar Beam, causing Ash to panic. However, the clouds cover the sun, which stops the Solar Beam from charging, giving Swellow the advantage; it finishes off Venusaur with an Aerial Ace. Despite Ash's latest victory, Scott warns that Spenser's last Pokémon is not to be underestimated. At that exact moment, Spenser sends out his Claydol. Ash orders a Quick Attack, but Claydol dodges it with Teleport, which leads into a Rapid Spin attack that hits Swellow hard from behind. Swellow regains its flight, only to be fazed by another Rapid Spin attack sending up a cloud of dust and sand, catching Swellow off-guard. Combining this with an almighty Hyper Beam, Claydol knocks Swellow out.
Ash and Spenser are now both down to their last Pokémon. Ash sends Sceptile back into battle to face Claydol. By this point, Team Rocket are hiding behind a mound of earth, next to Ash and Pikachu. Claydol uses Psybeam, which Sceptile manages to dodge. The Psybeam hits the earth in front of Team Rocket, blasting them off before they could have a chance to grab Pikachu. Sceptile then unleashes a Bullet Seed at Claydol, but Claydol dodges it with Teleport, which sends it out above the water, where it uses Rapid Spin to send a jet of water at Sceptile. Sceptile now jumps up onto the side of a cliff, as the sun behind Sceptile beams onto the yellow patches on its back, which start to glow. However, this is cut short due to a cloudy sky, followed by rain. A Rapid Spin from Claydol starts up a sand twister; Sceptile tries its best to avoid but is caught in the twister. Using this to his advantage, Spenser orders Claydol to use Psybeam at the twister, doing serious damage to Sceptile. Sceptile is sent flying and struggles to gain its feet again, slipping as it tries to stand.
The clouds start to part and Ash notices the yellow patches on Sceptile's back are absorbing the sunlight. Spenser explains that that phenomenon is called a squall. Later, the clouds depart, and Spenser orders a Hyper Beam from Claydol. However, Sceptile manages to avoid this by jumping out of the way, and Ash orders Solar Beam from Sceptile. Claydol is hit with a super-effective Solar Beam, which defeats it and gives Ash the win. Ash congratulates his Sceptile with a hug, which doesn't faze the cool Sceptile at all. Spenser congratulates Ash for an outstanding battle and awards him the Spirits Symbol. Scott approaches Ash, tells him that it is now time for him to head to his sixth Battle Frontier match, and warns him that his next opponent will be a tough one.