Red and Misty are at the entrance to Mt. Moon hiding in some bushes from the Team Rocket Grunts. They all have the same purpose, to find the Moon Stone, a rock with a moon-shaped inscription that can enhance a Pokémon's power. They enter the cave, but it is too dark to see anything. Red sends out Pika to illuminate the cave, and the darkness is no longer a problem. Suddenly, Red collides with a Rhyhorn, which turns out to belong to Team Rocket. The Grunts, along with Koga, surround them, and Red challenges Koga to a battle.
Rhyhorn begins with Rock Throw, managing to bury Pika, only for Pika to recover and fire a blast of electricity, surrounded by electrified debris from Rock Throw. The attack successfully knocks out Rhyhorn, but then Koga injects a liquid that forces Rhyhorn to evolve into Rhydon. Misty realizes that her Gyarados was similarly abused, and furious at Koga's nonchalant attitude she attacks the newly evolved Rhydon with her Staryu. Unfortunately, the attack is returned by Horn Drill, pushing Misty against the cave wall and causing her to faint. Rhydon stomps on Pika before moving in to finish Red, but Pika slides out from underneath Rhydon having charged itself tremendously. Using its tail, Pika cuts off a huge portion off the cave roof, blocking the cave and allowing Red a chance to escape with the others.
Outside the cave, Misty regains consciousness, while Red reveals that he pocketed the Moon Stone after Pika collapsed the cave.
In the VIZ Media first edition print, Misty hits Red accusing him of groping her as a result of him carrying her out of Mt. Moon after they escape. This is changed to her being angry that she's dirty in the second.