Team Rocket constructed a machine, which forced Pokémon at the Lake of Rage to evolve. One of them was a Magikarp, who evolved into a red Gyarados.
The Gyarados was enraged and was in pain. Thus, it started using Hydro Pump on the heroes, who tried to calm it down. The heroes, as well as Lance, tried to help it, but faced Team Rocket's forces instead. Jessie, James and Meowth were tasked of capturing the red Gyarados and went into the Lake of Rage, where they faced it. However, a net was launched and captured Gyarados and the trio; electricity was emitted to weaken Gyarados down. Ash sent Totodile and Misty a Poliwhirl to help it out, but radiowaves were emitted to make all Pokémon sick and unable to battle. The heroes were captured, while the red Gyarados was captured and being transported by Team Rocket's forces.
The commander, Tyson, informed Professor Sebastian the red Gyarados has been captured, but so did Lance to the police. While being transported by helicopters, the Gyarados woke up and shook the net, causing it to fall in the river. Using Hydro Pump, Gyarados destroyed Team Rocket's base at the Lake of Rage, then swam away. Ash tried to reason with Gyarados, who attacked him with Hydro Pump. Lance also tried to stop Gyarados, but faced Team Rocket's commander, Tyson. Gyarados, however, was captured by an electric net and even if the heroes saved it, Gyarados fell down from exhaustion and got captured by the trio, Jessie, James and Meowth. Gyarados became enraged and shook the net off, then started attacking everything around. It went to use Hyper Beam on the heroes, but was countered by an old man's Dewgong. Dewgong froze the river, stopping Gyarados, while the old man scolded the heroes for such dangerous attempt at stopping Gyarados. Gyarados, however, turned away and continued attacking. Lance went with Dragonite to battle the red Gyarados, who went on a rampage. Using Thunder Wave, Dragonite blocked Gyarados' Hyper Beam. Using Twister and Hyper Beam, Dragonite inflicted heavy damage on the red Gyarados, causing it to fall down. Fortunately, Lance used a Poké Ball and caught red Gyarados, then bid farewell to the heroes, as he flew with Dragonite away.
The heroes spoke to Clair how they met Lance and recalled the trouble with the red Gyarados.
Max, May and Brock, who jumped off Team Magma's ship, started to drown, after Kyogre attacked the ship. Thus, Lance sent his red Gyarados, who saved them. Brock explained to Max and May Gyarados belonged to Lance, a member of the Elite Four. Max and May were glad for such a friend on their side, while Gyarados took them to Monsu Island, where Ash and Pikachu, who were captured, were sent to. In order to stop Archie, Lance had Gyarados launch Hyper Beam against Kyogre's Hyper Beam. The heroes made a plan to distract Kyogre that Archie controlled; Max, May and Brock, while riding the red Gyarados, attacked Archie. Archie had Kyogre chase after them, as they sailed off. Once the Red Orb was pulled out of Archie, the red Gyarados came to the shore, where the heroes and Lance met up with each other.
|Hydro Pump||Talkin' 'Bout an Evolution|
|Hyper Beam +||Rage of Innocence|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
Marina, in "The Legend of Thunder! (Part 1)", imagined Lance with Dragonite and Gyarados, though the latter had a normal coloring.