On the way to Dawn's next contest, Piplup suddenly begins to show signs of evolving. When they arrive at the next Pokémon Center, Kenny and Barry are there as well. Dawn and Piplup must decide whether or not to have Piplup evolve into Prinplup, while trying to fend off Team Rocket who want to capture Dawn's Piplup, Kenny's Prinplup, and Barry's Empoleon to have a complete evolutionary set. (thetvdb.com)