The gang finally reach Mauville City, however Ash's Gym battle is forced to wait as the gang see an advert for a Pokemon Trick House, offering anyone who makes it through wih a lifetime supply of Pokéblocks. May is eager to win the prize, so the gang decide to enter, and meet up with a girl and her Whismur. But when Jigglypuff decides to perform her song, things may get complicated for the gang, and Team Rocket too. (thetvdb.com)