The two Johto trainers decide to join Ash, Dawn, and Brock on their journey. While on the way to Dawn's next contest, the group stops near the Valley Windworks for Dawn to do some training. When Marill goes missing, the group heads into the windworks to find it, but once inside they are attacked by wild Pokémon and become trapped. Will they be able to escape the building? (thetvdb.com)