Stairway to Devon

After winning the Stone Badge from Roxanne, Ash and co. head out to the next gym, located on Dewford Island. However, Max spills a drink on May's PokéNav and rather than suffer her wrath, Max tries to find a quick solution. He sees an old man demonstrating new inventions but before he can go further, a younger man picks him up in a limo. Who is this old man, and can he help Max fix the PokéNav before May finds out it's broken?