At Stark Mountain, Team Galactic Commander Charon has awakened the Legendary Pokémon Heatran, intending to have it destroy everything in the newly reborn organization's way. However, he and the two Team Galactic Grunts with him are forced to run away from the devastation caused by the Lava Dome Pokémon's awakening, leaving behind the Magma Stone that they had removed from its pedestal in order to achieve their objective. As they run away, Buck and his Claydol enter the cave as well and see that they were too late to stop Heatran's awakening. Buck has Claydol attack Heatran, but Heatran's counterattack easily overpowers Claydol's attack, slamming it straight into a wall.
As Buck tries to get Claydol back into the fight, Charon declares that he'll use Heatran to get rid of Buck for good. Heatran aims another attack at Buck, but before it can fire it, a Croagunk suddenly leaps in and knocks Heatran back. It then jumps back and knocks out the two Team Galactic Grunts, at which point its owner, Looker of the International Police, steps in and pets his Pokémon before telling Charon that his plans are over. Buck tells Looker that they must stop Heatran. Charon boasts that Heatran cannot be stopped and will scorch the entire Sinnoh region, but Looker delivers a chop to his neck, knocking him out.
As Croagunk and Claydol keep Heatran occupied, Buck asks Looker what they should do, and he returns the question in kind, frustrating Buck. Noticing the displaced Magma Stone, Buck decides to restore it back to its pedestal. Claydol starts lifting boulders with Psychic to create platforms for Buck to jump on while Croagunk keeps Heatran occupied with its Mud Bombs. Buck finally reaches the Magma Stone and lifts it up, and, just when Heatran is about to attack him, places it back onto its pedestal, causing a bright light to shine and Heatran to disappear as it's sealed away again. Buck thanks Claydol for its help and Looker compliments Buck's efforts. Behind them, the two Team Galactic Grunts have recovered and carry the unconcious Charon away before Buck and Looker can stop them.
Later outside on Route 227, Buck washes his face with water from a local river, before formally introducing himself to Looker. Looker thanks him for making rounding up the remnants of Team Galactic much easier. Buck assures that he'll be there to help Looker if he needs to be saved. Looker, while grateful for the offer, says that he doesn't think he'd lose to a young man like Buck. Hearing this, Buck asks Looker if he wants to have a battle.