The heroes arrive in a deserted town and get rejected by Nurse Joy to stay in her Pokémon Center. They soon find out the PMC, Ken and Mary, whom Ash and Brock encountered in Johto, are here after a mysterious Pokémon. Arriving in the Pokémon Center, the heroes encounter Team Rocket, as well as the mysterious Pokémon, Lunatone. They soon find out Lunatone is weak and can be restored if it sees moonlight beams. While the heroes go to the place to heal Lunatone, they encounter the PMC guys again.

After another encounter with Team Rocket, Ash loses Pikachu. Pikachu, however, has hit his head and suffers from amnesia and is found by Meowth. Meowth takes the opportunity and states Pikachu was one of Team Rocket members. Pikachu starts believing and once Ash comes to him, Pikachu turns his back on him. Ash, however, does not give up to get Pikachu back, and his memories.