DP122: Stopped in the Name of Love!

Plot
On the way to Dawn's next Pokemon Contest, Piplup suddenly begins to show signs of evolving, but it stops the evolution process with Bide and gets exhausted. When Ash and friends arrive at the next Pokemon 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.