Alain and his Charizard are on a mission to seek out and challenge Mega-Evolved Pokémon! They battle and defeat Astrid and her Mega Absol, unaware that they’re being watched. The observer is a young Trainer named Mairin, who’s just started her journey with her Chespin—and who has a lot of questions about Mega Evolution! Alain tells her he doesn’t have all the answers, but she’s still asking questions when he gets a call and has to leave.
She follows him to a cave, where he finds a Mega Stone. When he emerges, he’s challenged by Dragon Tamer Remo and his Mega Garchomp—with the Mega Stone on the line! Alain wins again, and afterward, Mairin tells him that she wants to learn to use Mega Evolution, too. But first, she’ll have to catch some more Pokémon!
Alain helps Mairin catch a Flabébé, and then he disappears when she takes it to a Pokémon Center. Nurse Joy tells Mairin that he went to a nearby restaurant to challenge the owner, Siebold of the Elite Four, and his Mega Blastoise. Mairin catches up just in time to watch the battle! The type disadvantage is too much for Charizard to overcome even after it Mega Evolves, and Alain is defeated—but Siebold is impressed with his strength. After the battle, Alain continues his journey, and Mairin is determined to go along with him and find a Mega Stone of her own!