On their way to Lake Valor for the Grand Festival, Ash and his Gang stop off for a break. Upstream, a Pokémon Ranger is attempting to capture a Heatran. Nearly captured, it flees before the capture is complete with the Ranger falling in the river. Saved by a Feraligatr, he greets Ash and company and introduces himself as Ben. He asks for their help in capturing the Legendary Pokémon and they agree. The feat will not be as simple as he wishes, for Team Rocket has also set their sights on the Lava Dome Pokémon. Will Ben and his new friends capture the fiery Pokémon and save it from harm or will Team Rocket finally get their clutches on a powerful legend?
The heroes are about to have lunch. Somewhere else, a Pokémon Ranger named Ben sees a Heatran using Eruption. He reports to his superior he will capture it and take it to the National Park and gets the permission. The ground shakes and Heatran goes away, but Ben spots a Pidgeot and captures it, then rides it to get Heatran. Just as he goes to capture it, Ben encounters a machine made by Team Rocket, who also wants to get Heatran. The machine digs out some rocks to get Heatran weakened, but it goes away and Ben and Pidgeot take damage. Fortunately, Ben uses his device to summon Feraligatr and rescues him, but they fall in a river.
The gang hears something and soon finds the Ranger on Feraligatr, unconscious. Ben wakes up and immediately introduces himself. He cannot find his device, but asks them if they saw a Heatran, who can use Eruption (as normally it cannot). Though they did not find it, Ben gets upset, but soon thinks that he still is a Ranger. He asks for their help and when the heroes agree, he immediately runs somewhere and expects them to follow him. As Team Rocket is depressed by not catching the Heatran, they soon find a device the Ranger used. Meowth thinks they could capture Heatran and give it for the boss to use for barbecues, fireplaces or sauna.
The heroes go towards the volcano where Ben first found Heatran. Dawn asks him how come he is so cheerful, with Ben replying that he remembers his family motto: "It is always better to try than cry", which came from his grandpa. Ben explains that he can try and things should go out well. He touches the ground to feel the temperature, as Heatran is attracted to volcano. After some time, they come to a cave and venture inside. Though somewhat disgusted by the Ranger's knowledge, Team Rocket knows if they were to follow them, they could use the device the Ranger dropped to capture both Heatran and Pikachu. While everyone feels the ground is warmer, Meowth burns his feet.
At the end of the tunnel, they see a large lava lake and on the top Heatran itself. Heatran uses Flash Fire ability to absorb heat. Ben has not a clue what to do next, as he should have caught it using his device. Ash proposes to use a Poké Ball, but Ben replies Heatran must be unharmed. He soon begins to panic, but has his confidence up. Soon, they are stopped by Team Rocket. James arms the device Ben dropped, but he is unable to launch the disk to capture Heatran. Ben lets him know that he is the only one who can use the device. James goes to throw it to Ben, but Jessie and Meowth remind him the Ranger would capture Heatran, so they use the machine instead.
They launch some nets, but Heatran's Eruption burns them. Heatran begins to lose balance, which could make it fall into lava. Ben decides to get the device back and take Heatran before the lava goes up. As he goes to, the ground is too hot, so Brock advises to cool it down. Piplup uses Whirlpool to cool a section down while Ash sends Buizel and Dawn her Buneary. With Water Gun, Ice Beam and Whirlpool, the trio cools down the ground even more. Team Rocket launches another net, but Heatran's Eruption burns the net down. The machine takes a different form and goes after Heatran. Heatran uses Eruption, though the machine defends itself and pushes the rocks towards Heatran, causing a portion of the cave wall to fall down.
Ben manages to get to James and takes his device back. However, Team Rocket goes towards him and he almost falls down, but hangs on a cliff. With Piakchu's Thunderbolt, Team Rocket gets electrocuted, so Ben goes up. The remote Meowth was carrying falls in lava; the machine goes out of control. While Heatran uses Eruption and destroys it, the cave wall falls and Heatran goes down with it. Ben summons his Feraligatr using his device, using Ice Beam on the lava. The lave tuns to stone and Heatran lands safely. The rocks begin to fall down from the ceiling, so Team Rocket runs away.
The place is dangerous to stay, so Ben captures Heatran and get out before the entire cave gets collapsed. Ben reports to his superior to come get Heatran. The gang is amazed he was able to get Heatran rescued and will remember his motto. Soon, Ben and Heatran are in a helicopter and fly away as Ash, Dawn and Brock wave hands before they depart.
- There is no Professor Oak's Pokémon lecture following this episode, instead being replaced by a trailer for the thirteenth movie.
- Despite having being a partner Pokémon of Ben in the Pokémon Ranger: Guardian Signs specials, Ukulele Pichu does not appear.
- Background music from Pokémon Heroes, Destiny Deoxys, and Pokémon Ranger and the Temple of the Sea is used.
- Similar to the previous two Ranger specials, the English dub of this episode followed a different order than the Japanese order when first aired, airing between A Grand Fight for Winning! and For The Love Of Meowth! to be closer to the release of its respective Ranger game: Pokémon Ranger: Guardian Signs.
- Unlike the Riolu specials, this episode was returned to its original position in the season after the first airing. However, Pokémon.com lists its placement in dub season 13 before Keeping in Top Forme! rather than after it.
When Brock says that normal Heatran can't use Eruption, Dawn's hat has some strange lines.
In the Japanese version the Narrator mentions during the opening and closing monologues that the gang are on their way to Valor Lakefront for the Grand Festival, however due to the dubbed episode being postponed so it could air nearer the release of Pokémon Ranger: Guardian Signs (at which point the gang were now on the way to Sunyshore City) both speeches are changed so that the group's destination isn't mentioned.