Curbing the Crimson Tide! (Japanese: 摩天楼の赤いイナズマ！ The Red Inazuma Skyscraper!) is the 21st episode of Pokémon: Battle Frontier.
Three children spot something in an alley. They identify a creature to be Red Lightning. Two of the boys think they should run, but the third wants to battle it. The Red Lightning wants the boy as a victim, so the boy sends Poliwag. The Red Lightning charges, so Poliwag uses Water Pulse, but Red Lightning evades and uses Hyper Beam, defeating Poliwag. The Red Lightning does something and flies away. The Poliwag has some scribbles on itself.
Meanwhile, the heroes came to a city. They spot a Pokémon Center and a mall, so May goes to shop. So, Brock, Ash and Max go to the Pokémon Center. Brock already flirts with Nurse Joy and Max pulls his ear. The children come as well, wanting Poliwag to be healed and scribble-free. They tell Joy Red Lightning stroke again. Joy and the children explain Red Lightning is a mysterious Pokémon who wears a mask and a cape, defeating other trainer's Pokémon and then scribbling on them. Max wonders why would someone scribble on Pokémon's faces. Another child comes with a Gulpin with the same problem. Team Rocket overheard that (dressed as cleaners) and want to get that Pokémon. Meowth is already pleased to get his hands on another talking Pokémon, though.
May feeds her Pokémon and does not know where to begin sight-seeing. May also gives her pink surprise to Munchlax and is pleased that she has a street full of shopping, according to the guide book. She calls her Pokémon back, but Squirtle disappeared. She finds Squirtle seeing some flowers with a Butterfree. However, a wind blows Butterfree away and a figure appears to her. May does not know it, so the figure introduces itself as Red Lightning. It wants to battle Squirtle. May wonders what Pokémon will it send, but is shocked when it tells it is a Pokémon and uses Hyper Beam. Squirtle evades and uses Water Gun. Red Lightning dodges, so Squirtle attacks again and misses. The Red Lightning's eye glows, locking Squirtle on the eye's radar and defeats it with a Hyper Beam. The Red Lightning scribbles on Squirtle and goes away.
Ash, Brock and Max see all the trainers with the scribbled faces of their Pokémon, including May's Squirtle. The heroes decide to go after the Red Lightning. While searching, they hear a girl and go to her. Her Chansey is also a victim of Red Lightning. May points at Red Lightning, who is standing on a fence. Ash demands an explanation and Red Lightning tells it - it wants to battle and wants Ash to battle as well. Ash accepts the challenge and sends Pikachu to use Quick Attack. Red Lightning evades, so Pikachu uses Thunderbolt, but he misses. Red Lightning uses Hyper Beam, but Pikachu uses Quick Attack to evade.
A net goes to get the Red Lightning, but Red Lightning evades. Team Rocket appears and Meowth fires another net. However, Red Lightning evades and hops on building to building away. The heroes go aboard the balloon to catch Red Lightning, as if they would fight Team Rocket, Red Lightning would go away. They spot Red Lightning moving, even if Team Rocket is angry for having the heroes. Red Lightning comes to a penthouse and a girl awaited it, but not the balloon. The heroes jump and just then the girl launches a tree, blowing Team Rocket and their balloon away. The heroes spot the girl talking to the Red Lightning, and the girl sees them. She is angry they came to her house. Ash apologizes, but wants to know why is Red Lightning attacking the Pokémon. She smiles and tells it is just a harmless fun.
Butler comes and Max tells the girl is causing trouble. The girl still does not want to know what her parents or the heroes think of her "fun". Since they are here, the girl decides to have a battle. Red Lightning uses Hyper Beam, but Pikachu uses Quick Attack to dodge and follows with Thunderbolt. Red Lightning counters with Swift and an explosion is made. The cape comes off and the Red Lightning is actually a Scizor with a collar to transmit what the girl was telling in the first place. Scizor uses Agility and Pikachu Quick Attack. Scizor navigates to the wind, but Pikachu cannot fly, so he stays on the ground. The girl tells her Scizor is one-of-a-kind since it can fly.
Ash sends Sceptile to battle it. While Scizor flies, Sceptile crawls on the windows of the building. Scizor uses Hyper Beam, so Sceptile uses Agility, but with the wind, it gets attacked. Brock now knows that the girl, Luna, is using the wind to push Scizor away. Scizor goes to Sceptile, who got his balance back. Scizor uses Hyper Beam, but Sceptile, on Ash's order, navigates to the wind. Sceptile uses Leaf Blade on Scizor and Scizor begins to fall down. However, Sceptile grabs Scizor and got to the penthouse. Luna is angry when Ash's Sceptile interfered, but the butler calms her down. The butler tells them Luna's parents are innovators and, when they became successful, they cannot be with her. Still, her Scyther evolved onto Scizor and the trouble began.
May comes and tells her she competes in the Pokémon Contests and meets a lot of people, but wishes to see Caroline and Norman, her parents and feels the same way as Luna. May proposes a battle and Luna accepts, gladly. Scizor uses Swift, but Squirtle withdraws inside its shell. Squirtle uses Water Gun, but Scizor dodges, leaving a puddle behind. May has an idea - Squirtle uses Ice Beam. Scizor evades, but because of the ice, it falls down. Squirtle uses Rapid Spin, and although Scizor jumped, Squirtle jumped as well and sent it falling down defeated. Luna thanks May for the battle and the Red Lightning myth exists no more. The butler heard May is a Coordinator and tells her there will be a Contest in Gardenia Town. May is thankful for that info.
- Oddly, Mime Jr. did not appear in Team Rocket's motto.
- 私、負けない！ 〜ハルカのテーマ〜 I Won't Lose! ~Haruka's Theme~ debuted as an insert song.
- The opening バトルフロンティア (Battle Frontier) was changed to スパート！ (Spurt!).
- Luna's house bears a striking resemblance to one in another episode.
- When May came to the Pokémon Center, the drawings on Squirtle's face changed.
- When Luna's tree missile sends Team Rocket blasting off, Wobbuffet's voice can be heard, but only Jessie, James, and Meowth are seen.