Last time we remember, Ash was fighting Blaine for the Volcano Badge. Pikachu was about to either be scorched by Magmar's Fire Blast, or fall into the pool of lava below. The Fire Blast passes over him, and when it clears, he is nowhere to be seen. He isn't dead, thankfully, but is clinging to the edge of the platform. Ash gives up, telling Blaine that no match is worth what could happen. He tells Ash to let Pikachu rest then leaves. Ash swears to Pikachu that he won't leave Cinnabar Island until he has the Volcano Badge, and they go back up.
As Ash cleans Pikachu up, Misty and Brock tell him that he should forget about the gym and come back some other time. Ash tells them that if Charizard would battle, he's be sure to win. On the other side of the fence, Team Rocket is underwater, practicing for the heat of the volcano. They review they're plan to catch Magmar to defeat Pikachu with. Meowth tells them that they'll pretend that Magmar has won a prize, and they are there to give it to him. When he has his guard down, they'll freeze him, and cart him off. They go down the stairs, and kick open the doors. Magmar appears, and Team Rocket quickly fires their freeze blasters at him, encasing him in ice. Unfortunately, Magmar melts the ice from around him. Team Rocket then fires the freeze blasts all over the place, covering the walls with ice. Ash, Misty, Brock, and Blaine rush down the stairs to see what's going on. Blaine tells Ash and his friends that all this ice on the hot rock could set off a chain reaction, causing the volcano to erupt. The whole room starts to crack apart, and Blaine explains that lava will flow through the rocks and the surge will cause an eruption. Holes appear in the wall, and the chains supporting the platform snap. Team Rocket is blasted through a hole by a jet of steam, and lava starts to burst through. Blaine tells Magmar to pile rocks into the crater to stop the flow, and Pikachu is about to help, but Blaine tells him that only Fire type Pokémon can withstand the heat of the lava.
Ash sends out Charizard and tells him to help Magmar. Needless to say, he doesn't listen and falls asleep on a rock. Magmar continues to throw rocks into the lava, but it doesn't seem to be working. Charizard opens an eye, and watches Magmar's strength. Finally, he decides to show off his strength, and starts to help. Brock sends out Geodude and Onix to help as well, and Ash and Misty send out Squirtle, Staryu, and Starmie to cool them off. Working together, they all pile more and more rocks into the path of the flowing lava. Togepi almost falls in, but Misty rescues him just in time. Finally, they are able to stop the flow. Blaine decides to give Ash another chance to fight him, and Ash quickly accepts.
The next day, Ash and his friends meet with Blaine at the top of the volcano. They agree on a one-on-one match, with Blaine sending out Magmar. Ash is about to send out Pikachu, but Charizard steps up. Ash sees the fire in his eyes, and Brock comments on how Charizard must want to show off his strength to Magmar. Magmar uses Flamethrower, which Charizard blocks with a Flamethrower of his own. Magmar then uses Fire Blast. After struggling with it for a few moments, Charizard is able to throw it up into the air. Magmar connects with a Skull Bash, and Charizard almost falls into the lava. He flies up, and dives down straight upon Magmar. Magmar then pulls both him and Charizard into the lava below. Ash protests, but Blaine informs him that the lava is part of the volcano as well. Ash stares at the lava, thinking his Pokémon is dead. Suddenly, he comes flying out and into the sky, with Magmar clinging desperately to his back. Ash tells Charizard to use his Aerial Submission attack. Charizard starts to spin, making Magmar dizzy. Ash then commands Charizard to use Seismic Toss and he flies high into the sky, then throws him straight at the volcano. Magmar plummets into the lava, and Charizard lands on one of the pillars. Magmar jumps out of the lava, and onto another pillar, only to keel over. Ash has won.
Blaine takes his wig off in a salute to the victor, revealing his shiny scalp. Ash commands Charizard to return, only to be scorched by a Flamethrower. Later, Blaine poses Ash with yet another riddle: What is always red, but has no words. He answers it himself right away, telling him it is a Volcano Badge. Ash doesn't get it, and the same goes for Misty and Brock. Blaine gives Ash the badge, and he continues on his journey. As they walk, Ash wonders where the next gym is. Brock tells him that there's one in Viridian City, but Ash didn't know this. He asks Misty why she never told him about it when they passed through, and she reminds him that they were fighting back then. However, she can't remember what they were fighting about. Unfortunately for Ash, Brock reminds her that it was the bike. Ash dashes off, with Brock and Misty soon behind.